KISS (keep it simple stupid), read lots of other people's code and see if you can understand it and if not what would you change? Adam Savage frequently mention

KISS (keep it simple stupid), read lots of other people's code and see if you can understand it and if not what would you change? Adam Savage frequently mentions a trick for makers that I think applies here: What would the future you think about that code? Would they feel nice having something extensible and not too complicated or be upset that the code works but is a mess to extend and fix?