Those are words I read off of a shirt that belongs to a girl in my Gym class. Notice how it says "your" and not "you're" as if you own the "not," and aren't simply being it.
I try not to bug people too much about grammar, but when you make a shirt, shouldn't you check your spelling and such? I also noticed this in a novel I was reading, a NOVEL! It was a good book, but writers should know the difference.
Your= Possesive
You're=You are