Are there anecdotes of non-absolute-beginners failing to understand that? For first-year students, sure. Do working software engineers have trouble with it? Do they have bugs and/or lower productivity because of it?
> If you can make the leap to "this is what an actual imperative program looks like nowadays", you can make a leap to declarative/functional programs just as well.
My own suspicion (completely unsupported by data) is that some peoples' brains find imperative languages to be more the way they think, and some find functional languages to fit their way of thinking better. You could run an experiment to test that - you'd take a group (call it A) of functional programmers, and a group B of imperative programmers, and measure their productivity. You'd then split the groups in half. A1 stays functional; A2 starts programming in imperative languages. B1 stays imperative; B2 goes to functional. Two years later, you measure everybody's productivity again. What I expect you'd find is that some of the people who switched (either way) increased productivity, and some declined.
What you might find is that everybody who switched from functional to imperative was less productive, but that might be because the (somewhat rare) people who are already functional programmers are almost exclusively the ones whose minds work better that way. You could fix that by starting with students or with fresh graduates, and arbitrarily assigning them to group A or group B. Then you'd have to wait a couple of years to measure their productivity the first time.
The difficulty, of course, is figuring out a way to at least somewhat objectively measure their productivity...
Sorry, I was unclear: I was talking about beginners. My argument was about intuitivity and "it's easier/harder to learn programming this way". Software engineers are already down the road of "I'm used to this, therefore this is the best way" :P
If I understand you correctly, what you say is entirely possible: that some people think best one way or the other, and that there is no universal paradigm that is more intuitive.
I don't recall ever having trouble with that myself, but that's anecdote, not data...