I recently got assigned to enhance some code I've never seen before. The code was so bad that I'd have to fully understand it and change multiple places to make my enhancement. I decided that if I was going to be doing that anyway, I might as well refactor it into a better state first. It feels so good to make things better instead of just making them do an extra thing.

Just be careful that 'better' doesn't just mean 'written by me'. I've seen that a lot too