For the last 6 months I dived deep in the open-source world. I cried so many times. Lack of recent documentation, a lot of products having multiple ways to install, almost nothing works out of the box and requires additional tweaking.
But... Man is it bloody fast.
After Windows everything seems to have doubled in speed.
C++ is freaking awesome (still feeling disgusted from the syntax though unless it's modern)
And emacs... I'm having a hunch, it was supposed to be it's own operating system for some reason ;D