I think a good role model understands that everyone has some level of influence on someone else.
They understand that everyone's' actions and behaviors affect someone else in one way or another.
They understand that someone is ALWAYS watching and because of that understanding they try to ensure that the behavior they emit is used to promote the best interests of the other person.
I don't necessarily think that a person had to be a part of a formal mentoring program or anything to make a positive difference in someone's life.
You can affect someone in huge ways by just doing little things: through what you say, or don't say, smiling, asking about someone's day, saying hello to someone on the street, or by just having someone see how you carry yourself when you're out.
And this is something I never really understood with artists and celebrities. They always say, “I'm not a role model,” and try to weasel their way out of it – like they get pass or something because they're a celebrity. Which is crazy to me because THEY'RE THE VERY ONES YOUNG PEOPLE ARE WATCHING!