The time I persevered was when I learnt how to solve a 3x3 Rubik's cube. It may seem impossible, which was exactly what I thought of at first. However, after watching a tutorial and sort of figuring out what the rough idea was, I began. Memorization was the hardest part of the process, I spent 40 minutes, which felt like an eternity. It was like a riot of colours in my brain, mentally juggling all the 54 different stickers and their orientations. Once that was done, everything was significantly easier. Using a set of algorithms, I was able to "move" the pieces around on the cube. After 10 minutes, I took off my blindfold. I felt so, so, accomplished.
I was glad that I persevered.
(i forgot how to solve it now lol)