Like alot of things in my life i see it in the sense of music, lol.
The same is performing on stage infront of your peers and completely random people. You get the fear of what if, but then adrenalin(or some other effect) builds up and you go for it and it feels great and becomes addictive and you try and push your self higher and higher.
For most vanilla people singing on stage infront of 100's of people can make you faint but there are those who become junkies off of it. Same sitch.