I've had those, too. Let me use an analogy to explain.
Remember those "Choose Your Own Adventure" books, kid's stories from the early '80s? You may have read them; I did. Check out the
Wikipedia article if you haven't heard of them, or if you have a want a great
call-back.
Well, with these things you would make choices while reading the story, and turn to different pages depending on your choice, and read a different
continuation of the story from that point on. And so on, with more choices, and lots of different endings.
When reading them, I would always, upon encountering a choice for the first time, stick my finger between the pages, as a sort of temporary bookmark.
That way, if I reached an ending or wanted to backtrack, I could. Sometimes I'd get many fingers in there, as the choices led from one to
another!
Anyway, here's the analogy: I've always thought of philosophy and reasoning as a sort of 'Choose Your Own Adventure' book. No, not the
relativist fallacy, as ALightinDarkness might quickly point out, but as a technique for ensuring complete traversal of the subject matter, when
definitive proof was lacking -- quite often the case, in philosophy.
So, to use the analogy, I remember, in 9th grade English I think it was, we discussed for the first time in school the concept of
solipsism. I found it fascinating, but I couldn't decide if it was true or not. The class quickly
moved on to other subjects! I felt that something important had been glossed over, so I 'stuck my finger in the book', marking solipsism as an
unresolved issue.
That was many many years ago. I learned a
lot, studying more philosophy, logic, aesthetics, etc. I ain't no Leonardo, but I likes me books.
College came and went, life went on.
Eventually, I came back around to
epistomology, and, to my surprise, I remembered that I still
had that finger there, bookmarking that page.
I though I'd had major existential crises before. You know, teenage angst and all, what's my place in the world sort of stuff. I was wrong. I
realized then, that no matter if I lived a hundred or even a thousand years, I might never get my finger out of that book. I struggled against that,
felt doomed at the uncertainty of it all. Powerless.
Eventually, I learned to deal with it. Resolved the paradox, don't ask me how.
That was my first major experience with existential crisis.