The Magical Age

I've been thinking lately, how old is too old? When are you too old to watch Phineas and Ferb, or play house? How old is too old to still be watching Hannah Montana? When should NERF guns be put in a box up on the shelf? When is the proper age to pack up the beanie babies and baby dolls? When do you trade in the convertible for a minivan? When are you too old to be "in style"? You're only as old as you feel you are right? Sometimes, adults seem to use phrases that were cool a few years ago, just to seem in style, but when you hear a grandparent say something like "Legit", we automatically think, "wow, did they really just say, 'legit'?" That is so not in style... don't try to argue the fact, because you know it's true. What age did they reach, when saying "legit" stopped being cool? Is it a predetermined age that was set before the generation of today began? Honestly, when do we become old? Is old an actual age, or just a state of mind?