I made a list of my improv experience because I get asked the question a lot. Now, easy for me, I can just give people that link. That list can be taken a few ways and "Holy crap that's a lot of training!" is pretty much the sum of it. I have many reasons why I started doing improv:

I started taking improv classes because it looked like a lot of fun.
I was doing improv because I loved being on stage.
I do improv because I love making people laugh.
I now do improv to hone my craft as an actor.

I think improv gives folks a lot of tools for public speaking, talking to strangers, talking to someone you have a crush on, and performing on the stage and on screen. I know I can get pretty wrapped up in the mechanics of improv which is both good and bad. Right now I'm using improv as a tool to strengthen my scene work as an actor. Currently, I'm also a member of 2 independent improv teams which allow me to have fun with improv.

There are a lot of topics I'd like to cover about improv:
Improv and Self
Improv Community
Improv Teams
Teaching Improv
Schools of Improv
Improv Forms
My Improv Heros