It became a habit to cry over a B+.
It became a habit to get angry when shots don't go it (basketball).
It became a habit to tear some paper away from my notebooks, because of my handwriting and that one mistake I made.
It became a habit to mess up my sleeping schedule, just because I haven't finished my do's for today.
It became a habit to look at the perfect body and realize: "I will never be as perfect as she is."
It became a habit to repeat many maths tasks, just to get the idea of how it should be. It became a habit tot listen to the monster inside my head.

Perfectionism is the habit.
Perfectionism is that monster inside my head.