"I was haunted by the possibility that the thing had no answer at all, and by the even more dismaying thought that the damn thing was simple and I just couldn’t see it. Am I stupid to keep trying or stupid to not be done yet? Either way …"

This resonates so much with me. This is the biggest gulf between doing very hard assigned problems and original research.

Just knowing that a problem is 'at your level' really helps me with solving it. Any failure becomes a temporary setback, rather than an indication that maybe I won't be able to solve this.

I've tried to meta-game myself on this, simply by assuming the solution is achievable. It gets ever harder the longer a problem goes unsolved though. Simply because it takes more effort to ignore the 'evidence' suggesting the problem is hard.

Honestly, I quit mathematics for the very same reason. And, like the author but to a greater degree, I didn't have the strength of will to keep at it.

Funny, quite a few friends of mine like that who quit mathematics. But we're all better off materially for having done it.

Contemporaneous discussion: https://news.ycombinator.com/item?id=13276968

Well written piece of quit-lit, but the funny thing is the author barely touches on how lucky he was to quit when he did. In the intervening years academia devolved further into toxicity. Rather than wistful, the many-worlds version of this narrative where he stays would probably be a rage filled diatribe.

Wow "the hardest part is controlling your emotions."

"You didn't fail Bob, you quit."

Was physics just as streesful for him as it was for me?

There is a lot of food for thought.