after having to deal with a lot of weird "rewrites" and "refactorings" by co-workers i started to add this comment into the head of my sourcefiles:

You may think you know what the following code does.
But you dont. Trust me.
Fiddle with it, and youll spend many sleepless nights cursing the moment you thought youd be clever enough to "optimize" the code below. Now close this file and go play with something else.

Found this somewhere on the interwebs and since i use it the "refactorings" and "optimizations" of my code stopped nearly completely