Edit: not the kernel or the GNU utilities themselves, but rather some people on the various affiliated forums. While most people have been kind and helpful, a handful of bad apples don't know how to behave. They are hostile to the point where one could easily lose the will to have anything to do with Linux.

I have only ever been positively surprised. Just a few of all the good habits that Linux has made me adopt:

1. RTFM
2. Reading logs
3. Keeping/reusing old hardware