I never turn on the radio because I'm trve and kvlt (I've also never heard Soundgarden or Pearl Jam).
Nirvana was my favorite band before I discovered Opeth (so around 15 years old). I had most of their stuff (including Incesticide) and enjoyed all of it because I was a fanboy. It would be interesting to go back and re-assess at this point because I haven't listened to much outside of the MTV Unplugged album in a long time.
I don't know. The musical progression of those 3 years makes no sense: 14 y/o - Creed, 15 y/o Nirvana, 16 y/o Opeth. After that I actually diversified and listened to a lot of different bands. Not sure how I first stumbled across Nirvana.