I'm fourteen!
This is a phrase used when you are at Mandalay Bay and are over the age of 14, but not willing to pay the extra fee for pool access.

It also can be used at other times if you're wanting to sound young. (Not for use if above 18 years of age)

Funny to use in response to any question asked.
Man at counter: How old is this kid?
Overage kid: I'm fourteen!