The superhuman feeling of going back to your code after a week and it all makes perfect sense, the variable names are intuitive, the doc strings are comprehensive, and the general codebase structure is sensible.

Yessss! It feels awesome.

When I was younger I just dove into all of my programming projects headfirst, no planning whatsoever. Sure, I learned a ton, but going back some of the things I did make me physically cringe.

Even the very first time that I planned out a project's base code with pen and paper, I was blown away at how well things went. Not flawlessly, but with a fraction of the time, errors, and aggravation that normally comes from starting a project.

+1