Jack Black isn't a good teacher.
The School of Rock star - who also fronts rock group Tenacious D - has been trying to teach music to his young sons Sammy, nine, and Thomas, seven, but doesn't think he has the right temperament to pass on his knowledge.
He said: ''I've been trying to teach my boys how to play instruments but I've discovered I'm not a very good teacher. It takes a certain patience that I don't know if I'm gifted with.''
The 46-year-old actor - who is married to musician Tanya Haden - is a devoted father and would rather skip a night out to spend time with his boys.
He told Britain's OK! magazine: ''Last night I was going to see a movie and I was thinking, 'I'd just like to go home and put my boys to bed. Why am I going out to a movie?' So I did a U-turn in the car, went home and talked to them about their day at school. They've just started school so they are a little stressed. Talking to them about their day, that's what really gives me joy.''
But the Kung Fu Panda 3 star hopes his sons don't follow in his own rebellious footsteps.
He said: ''I'm in trouble. I hope they're not going to be like I was, but I know they probably will be. We'll see.''