To me, there is no greater high than seeing big negative numbers on a commit. Deleting stuff is the most satisfying experience in programming. A commit with +10, -142 is mint.

Be careful with that one. I'm not sure about your experience level, but a mistake newer (and some more experienced) programmers often make is taking DRY too far.

It's easy to "dry" something up to the point where it's spaghetti that's overly clever about how it reduces lines of code resulting in some crazy inheritance hierarchy even you (the author) are afraid to change a few years down the road.

There are of course other times when someone just copy and pasted e.g. sort logic all over the code base ... but that sort of thing is relatively rare