Horrible experience with Ubuntu 8.04 as a liveCD to install PureData Extended and mess around with it.
Everything was breaking and I couldn't find the cause, little did I know that it didn't give me a warning when the virtual filesystem (which was entirely located in RAM) was getting full.
Went to the #ubuntu channel on freenode and started asking around, that's when I came in contact with the shell commands. I had no idea what I was doing, and what power the commands had when ran with the right privileges. So I accidentally wiped a whole system partition. That's where I learned the powers of the shell... The hard way.
All in all I swore never to touch Linux (-related OS'es) again until a friend of a friend of mine sat down with me and explained the basics of how Linux worked and the power of the shell. I was amazed at the flexibility of the system and that's where I learned the powers of clear explanation
Afterwards I picked up a book called "
How to teach yourself UNIX in 10 Minutes" and everything went better than expected. Fast forward a couple of years and I bought a cheap dualcore Atom netbook and installed CentOS 5 on it to experiment with various stuff on it like web hosting.
I am still using Windows as my main OS but that's primarily because of certain DAWs (Ableton Live in particular). However, I'm still interested in learning about *nix systems because I'm always eager to learn things which I don't understand yet.