Part of being a good programmer is knowing when you are writing bad code. In my mind its subtlety different, I never plan to write bad code, but sometimes it just turns out that way because of a tiny initial bad decision.

That is what sets good and bad programmers apart. Bad programmer have no clue that they are writing terrible code.

Not just writing bad code, but learning from the bad code so you can solve a similar problem in the future with better code.