Why do people get sleeve tattoos?

I went into a tat shop with my then girl friend to inquire how much it would cost to get trained using and ink gun. She was already versed using soft tap method for permanent makeup. Through conversation when the owner discovered how much she made doing "procedures" he told us to get out.
I've always heard if you are ever interested in getting one, put a picture of it on a wall you see everyday. After a year if you still like it and want to get inked then do it.
It would be kind of bad ass to always wear a suit over a totally cover upper torso and arms.