I wanna diet my hair

So, just now, this was the conversation had with the four (going on 21 year old):

"Mom, when I get older I want you to diet my hair"

me: "why?"

"because"

me: "what color would I dye your hair?"

"you know that girl at the concert with the pink hair with a little bit of brown?"

me (searching my memory that doesn't always work as fast as it used to - then stopping at a mental image of a woman we saw with a shockingly deep shade of fuchsia hair): "why do you want your hair pink and brown?"

"oh, because it made her hair look good and I want mine to look good too when you diet it."

Does it ever amaze you that what they say is so many years beyond the language they have to express themselves?  I'm trying not to be too concerned for the teenage years just yet...