First, of all the hundreds of little insights, interesting trains of thought, and connections made between previously unrelated ideas, there is one revelation in particular that floats to the top of my mind. It's this: LSD confronts you, in an extremely visceral way, with the fact that the entire universe that you perceive and interact with, the whole world and everybody in it, is entirely in your own mind at all times. Sure, it's perfectly reasonable to believe that it's all derived from an objective, external world - but you've never interacted directly with that one, and in fact you can't.
Now, you might say that you already "know" this, philosophically. You can even do the smug, Internet know-it-all thing and say this is completely pedestrian, name-drop Descartes and a bunch of other philosophers, and hit me with a zinger about how this is about as deep as "The Matrix". But I'm not claiming that LSD leads you to the philosophical idea; I'm saying that it slaps you right in the face with it, viscerally. It doesn't tell you, so that you have to think about it in the abstract; it shows you, literally with your own eyes. It's the difference between knowing what the Grand Canyon looks like from pictures, and standing on the edge of it.
It is very common for people to describe the onset of their first trip in terms of waking up, for the first time, ever. I'd describe it this way, too. It feels like waking up for the first time, and realizing that you'd been dreaming your whole life. Of course, this is really just an analogy, and it's more than just a feeling. It's a sudden shift in your actual perceptual processes, which are largely chemical, and have now been altered. But by the mere fact of them being altered, you realize that the default way of perceiving is just that - just a default. It isn't more "true" or more "real" - it's a default, it's massively culturally constructed, and it's characterized by a certain amount of non-questioning of assumptions. What's a color? What's a country? What's a "week"? What's a leader? What is solid? Which way is up? What's a job? Your brain starts trying to decompose every concept into basic principles, and you realize that for a lot of things in the human world, there are none. Just made-up, widespread beliefs that cause lots of people to act as-if, and in so doing, make them "real". Again, there is a difference between merely realizing this philosophically, and being transported outside of the web of culturally-reinforced beliefs and observing it from the outside.
So there's a lot of shedding of constructed concepts. What's left when all that chaff blows away? Whatever it is, it a) seems a lot more real, and b) is obscured in normal consciousness. I'm not suggesting that it would be desirable to permanently lose the ability to think on the level of appointments, check-writing, stop-lights, prospectuses, and the rest of the "mundane". I am definitely suggesting that what is left of experience after all that is obliterated from consciousness is worth seeing. There are parallels here with Buddhism and enlightenment traditions. It's also extremely common for people to offer meditation as a substitute. It's perfectly fine if you don't want to do illegal drugs - hardly anyone will fault you. But don't fool yourself that you're getting the same effect. I've practiced meditation too, and while it does alter consciousness, there are many meaningfully different altered states - they are in no way equivalent or substitutable. (Think about it - if you can simulate an LSD trip by meditating, do you simulate a K trip by meditating differently? Can you meditate yourself to a heroin high by a different technique? LSD isn't just another interchangeable "enlightened" state - they're all specific in their sets of effects. I have no doubt that I too have missed out on plenty of profound experiences by not taking, doing, seeing, or achieving any number of things. It's a big world.)
Sadly, this is turning into a wall of text, and I could still go on for the rest of the day. So, I'm going to force myself to wrap up with just a few more short highlights:
* I learned OpenGL while tripping. The subjective experience was of the information slipping into my brain effortlessly. Normally, I have to read sentences and paragraphs multiple times for them to "sink in". That time, I just skimmed, and understood. The next day, sober, I wrote a couple of neat height-field/terrain programs in OpenGL. Of course we've all learned dozens of even more complicated topics without any drugs, so this anecdote is meaningless, right? All I'm talking about is what it felt like to learn it. It felt effortless by comparison to the way I normally learn. Placebo? Selective memory? Your other favorite bias? Might be interesting to know definitively - but I still had a really good time that night.
* I once won a game of Mastermind on the first turn, without making any other guesses. This seriously freaked out the other people at the table. I wasn't tripping at the time, but I was in a distinctly "trippy" mentality - so much so that I was having a mini-flashback by the end of the turn. What I had done was to realize that the room was a closed system, containing the information about the winning pattern, and that as part of that system, I might have access to the information via other channels. Basically, I just paid very close attention to the other person's body language as I fingered different colored pegs, and allowed him to inadvertently "tell" me the correct colors and order.
* I once did a drawing of a woman from the neck up, while tripping. When I started drawing her hair, I got lost. I was drawing hair for what seemed like hours. I was hiding dozens of other, nested, drawings inside the texture of the hair. It still looked more or less like hair, but if you really looked at it, it was teeming with a whole bunch of unrelated drawings. Sure, I could do the same thing now, but it had never before occurred to me to try that. There is something about tripping that is inherently amenable to that kind of recursive, fractal thinking.
In short, don't knock subjective experiences. The enjoyment of music is a subjective experience, is it not?
To me one of the more present dangers of the "acid experience" is that the tripper latches onto the alternate state they experience and devolves into crapping on about chakras, energy fields, or little elves that live in their garden; the real lesson, as you've rightly identified, is not that the new experience is objectively real - it's that our "normal" daily experience is entirely subjective.
It's not necessarily the most natural conclusion, however, and I suspect that maintaining this kind of scientific (read: sane) outlook becomes increasingly difficult with frequency and intensity of use.
While I've personally never tried LSD, my favorite is, e, which offers a similar, but different, opening of the mind. Since I've never tried LSD, I can only say that e opens one in an emotional way, one that allows you to empathize and understand the universe in a way that you otherwise wouldn't. It also invokes an odd existential dialog within oneself about how the world works and why we think the way we do.
I suppose I quote you because as a musician and software engineer, it is often the case that I ask myself why it is that certain things are the way they are. For example, anyone that's studies AI realizes that one of the harder concepts is that of _understanding_.
How do we make a machine understand when we ourselves don't understand the _why_ around us?
Drugs like e and LSD present an insight to us that allows us to realize that the answer is a lot more distant than just what we perceive.
I read it cover-to-cover in about 2 hours and I thought it was the most amazing material. The structure of that book is very much like the thinking process of someone on hallucinogens, or rather, a dialogue between a person on LSD who's babbling and a completely sober person trying to refute the babblings. It ends up making sense though.
Wittgenstein wasn't eating any hallucinogens as nice as that might be to consider. The structure of his works follow the thinking process of somebody who has grasped intersubjectivity at an unprecedented level.
Sounds like a day with a toddler ...
Excepting the fact that mine have never got in to the "why" phase (I blame my need to over describe and analyse everything and constantly ask them why) - breaking down concepts gets complex pretty quickly. Explaining a day off turns in to the complexities of royal [male] succession. Life's fun.
He said it perfectly when he said it "slaps you in the face" with this idea.
It's like all your input filters and mechanisms for categorizing things are stripped away, and your mind just gets raw input - filters you normally don't even realize are there.
This makes a speck of dirt on the floor just as interesting as the hot chick standing next to you - and it can make it difficult to impossible to utter a coherent sentence, let alone put together a coherent thought - it's more like raw, pure sensation, unfiltered.
Of course, there's the psychedelic part, with visual disturbances and sensory weirdness too.....
There is no guarantee of good feelings or euphoria like you get with E.... it can best be described as simply "an experience"
this epiphany occurred to me through a drug induced change in consciousness. i realized that every material thing in this universe is just a product of my consciousness. this then got me thinking: how is it that material is a product of my consciousness, yet science tells me that my brain (a piece of material produces consciousness).
I flirted with this paradox for months. I concluded that everything in the universe is just a system of interconnected systems of the same energy. I thought of the things in the universe as just different manifestations of a single type of energy at different points in space and time.
Then I read about Amit Goswami and learned some very useful scientific jargon for what i was experiencing. Anyone who is interested in "conscioussness" should research this man - he is leading a thought revolution
I can definitely sympathise with the flavour of insight you're talking about though, and this guy seems to hold some credentials, but phrases like "make brain circuits of positive emotions" trip my hippie detector.