Cool! My dog Bailey is extremely scared of them. He would literally follow me everywhere--in my bedroom. Even if he was lying on the couch and I got up to go in the kitchen--he'd get off and follow me when it's like 3 feet from the family room.
I was able to tell he was scared 'cause he has never followed me everywhere so much before.
It's perfectly ok to be scared of thunderstorms and their is nothing childish about it...Heck I am scared of balloons!!!....So its totally fine!
And to answer your question......I am not scared of thunderstorms (although I used to be) I think there is something mesmerizing about them now :)