You're missing the point of leetcode practice (as stupid as the practice is, to begin with). The idea is to recognize patterns in different types of problems and general solutions to those patterns. Brute forcing your way through hundreds of problems with the goal of memorizing solutions is absolutely the wrong (and incredibly time-consuming) way of doing it.

To recognize the patterns, you need to memorize the patterns

Yes! Just don't fall prey to pareidolia or paranoia.