A couple other people have jumped on this, but it's also worth pointing out the specialization that goes on in the field now.
For example, I'm almost exclusively writing web applications, and have been for years (coming up on 15 years soon).
Granted, I do know a bit of C and some other more systems-y languages (and more than a little bit about the underlying implementation of Python, which is the language I prefer to use), and I even know a fair amount of underlying fundamental theory, but... ultimately my brain is of finite size and I have only finite time. So I have to prioritize like everyone else, and choose what I will spend time learning and what I will devote brain cells to remembering.
The result of this is that there are things which, to someone outside of web development, would seem horribly arcane and irrelevant, but which I have to know, and as a result there are things those other people have to know which, to me, are horribly arcane and irrelevant.
And the further result is that when I see people wading into web development from other fields of programming, I often see them make mistakes -- sometimes big, security-hole-opening, money-losing mistakes -- that are on par with someone blundering into C with no knowledge of pointers, memory management, bounds-checking, etc.
So just remember that what seems hugely important and required-learning to you may not be to someone else, and that something which seems irrelevant to you may be hugely important required learning to them :)
For example, I'm almost exclusively writing web applications, and have been for years (coming up on 15 years soon).
Granted, I do know a bit of C and some other more systems-y languages (and more than a little bit about the underlying implementation of Python, which is the language I prefer to use), and I even know a fair amount of underlying fundamental theory, but... ultimately my brain is of finite size and I have only finite time. So I have to prioritize like everyone else, and choose what I will spend time learning and what I will devote brain cells to remembering.
The result of this is that there are things which, to someone outside of web development, would seem horribly arcane and irrelevant, but which I have to know, and as a result there are things those other people have to know which, to me, are horribly arcane and irrelevant.
And the further result is that when I see people wading into web development from other fields of programming, I often see them make mistakes -- sometimes big, security-hole-opening, money-losing mistakes -- that are on par with someone blundering into C with no knowledge of pointers, memory management, bounds-checking, etc.
So just remember that what seems hugely important and required-learning to you may not be to someone else, and that something which seems irrelevant to you may be hugely important required learning to them :)