Advent of Code 2021
I really enjoyed the early part of this last year, but I got to Day 19 and suddenly it became"if you memorized some mathematical concepts and an obscure algorithm and also recognize that this exact algorithm is the only efficient solution to the problem then you can solve this in 5 seconds, otherwise it will never finish running with any other algorithm".I immediately quit.  I'm not doing these to prove I'm smarter than other people or memorized random math concepts, I'm doing this to practice writing code or to learn a new language.Not sure if this is indicative of other years (This is the farthest I've persisted in the 3 I've tried) but it was EXTREMELY demotivating, and killed every desire to continue or to even try it again next year.*EDIT*:  Apologies, I was incorrect on the Day where this happened.  It was actually Day 13, with the Chinese Remainder Theorem being the solution.  I must have copy/pasted a solution in frustration and continued past that point.  My mistake.