Over a long period of time, Rainbow Dash has instilled into her mind this complex ignorance of all things uncool, the most significance being negative emotion. She likes to believe that emotions like sadness and hate are things which she shouldn't bother with.

So her solution is the hide them all, lock them away deep inside herself in a place where she shouldn't have to worry about them anymore.

Only there is a problem.

Sometimes, you can't bottle yourself up forever.

-Accepted into Twilight's Library