Omg! I just read that Zac Efron is like 19!

And Ricky Ullman (Phil from Phil of the Future) is 21!! Omg! Sorry! But I just cant believe it. Why do they cast really old actors and make them look so young?!
And if anyone asks, I didn't get up at 5 to 5 in the morning to post this. lol. Im going on holidays this morning so ive stayed up. =)
Obviously, Im very hyper.