I always leave work at 9:30
Thats when the shift ends.
Because I'm not a working class
Work is ultimately a means to get money, so it's good to know when to leave. This way, your superiors don't take advantage of your time for no compensation.
Well, I don't work there to make money. I work there to make people happy.
I am glad you enjoy your job. Don't get burned out though if you really like it. You may come to resent after time if you let others take advantage of you.