It's strange to see this topic, since I was recently thinking that the people I've been looking up to aren't really great people to idolize, and I now wonder why I ever wanted to meet them.
I think the closest was Betty White, and I didn't actually meet her personally. She just gave me a wave.
If I did meet someone I idolized I would probably get starstruck. For example I saw Betty White on a middle school field trip and 6th grade me could not have cared less. My teacher was gushing though.