You can play older than yourself. You can play younger than yourself up to a point, and then that just becomes impossible because you carry a weight with you that you can't shift, unless you have very boyish looks. ↗
Young people can be disruptive and screw up classes. But even if they are being a pain in the arse it's a cry for help - they don't feel like they are being listened to. ↗
I was never challenged when it came to acting as a youngster. I sort of just did whatever was given to me without asking questions. I didn't really understand why I enjoyed it or why I did it. ↗