I gotta admit it takes a lot of guts to fess up things like this. I looked at the "Stupid Things We Did" and was shocked at how stupid some of it really was considering that these people were calling themselves founders and even had investors. But then I suddenly got reminded of how I once spent a week creating a scrollbar from scratch in ActionScript for a product that nobody cares about now. I've also spent a lot of time writing my own libraries because they are cleaner/more-efficient than existing utilities out there only to throw them out completely because the specs changed. Had I used a slightly bulky off-the-shelf library, I would have saved a lot more time and could have replaced it with my own code if the library caused a bottleneck.

As I work on my new project now, I keep asking myself "Is this actually going to matter to anyone except my OCD-self/ego?" If yes, then I do it. I've wasted too much time because I'm a stickler for file-naming-conventions or got stuck with one weird bug that only affects 0.1% of my target users.