Every time I think I came up with something new, I would later find out someone beat me to it.
Happens a lot to scientists who move to a new field. It means that you are not stupid and that you are not familiar with the literature. But you have to be familiar with what is being done to be productive.
My intuition is that this happens more in philosophy than other fields. I, an amateur, have thought of multiple questions and arguments which I later come to find have already been explored in the literature. I've seen students in undergrad classes anticipate moves made by famous philosophers. I hate telling this to my friends who are pursuing graduate studies in philosophy, but I think the explanation for this is that philosophy is just easier than more technical fields like math and physics.
I, an amateur, have thought of multiple questions and arguments which I later come to find have already been explored in the literature. I've seen students in undergrad classes anticipate moves made by famous philosophers.
It's bizarre to me that you treat this as an indication of philosophy's easiness and not its difficulty.
Why should it indicate difficulty and not easiness? A similar feat would be completely beyond me in math. Even though I minored in math as an undergrad, I have almost no understanding of the questions and arguments being discussed in the professional mathematics literature. I'm never going to stumble across one of my personal ideas in the Annals of Mathematics. It requires so much dedicated time and effort to even understand what is being said.
The professional philosophy literature, on the other hand, is much more accessible. Philosophers treat familiar questions like "Do we have free will?", "What does it mean to do the right thing?", "What does it mean to know something?", etc, in a qualitative manner. After a minimal investment to understand some of the jargon, most philosophy papers are quite readable. It's the kind of enterprise that a layman might actually be able to make an intelligent contribution to.
Happens a lot to scientists who move to a new field. It means that you are not stupid and that you are not familiar with the literature. But you have to be familiar with what is being done to be productive.