Absolutely, I've been stuck on one problem for years now (why I haven't just abandoned it is another matter, the long story short is that I just can't) and yeh, like you say, I've been in some deep pits I can attribute to that, and I do find myself, especially but not always in those times, looking at others in the same field doing so much better seemingly effortlessly. But those times I get a glint of a solution, even if it doesnt end up becoming anything, are incomparable to any other hobby I've ever had. Whether thats worth it is up to the individual I guess, but I think for most people, when they find "their thing", it usually is, or at least isn't something they can choose not to do.

Can't have the rainbow without the rain as they say