It came last year, during a panel discussion at the Denver Comic Con. A little girl asked Wheaton how to deal with being called a nerd by her classmates.
Wheaton said in part, "When a person makes fun of you, when a person is cruel to you, it has nothing to do with you. It's not about what you said, it's not about what you did, it's not about what you love, it's about them feeling bad about themselves… But there's 50,000 people here this weekend, who went through the exact same thing, and we're all doing really well."
The girl's mother says Wheaton's words really helped her daughter.
You can watch the full response here: Wil Wheatons response to a little girl on how to deal with being called a nerd
