I think it's brilliant advice to young people to not try to seem like an expert when they clearly aren't one. When you're dealing with people who are familiar with your subject, you can't fake it until you make it - you're 22 and they have a pretty good idea of how little a 22 year old is going to know.

The good news is that also means they have reasonable expectations of you - be helpful and thoughtful, and they'll appreciate it. Bullshit like you know everything, and they'll think you're a dumbass.