I never understood this. It's not like the company will ever hire you back. It's not like you'd want to go back. I give companies the same treatment they give me: I don't owe you anything. I leave anytime I please. Once I got a job offer during my shift and I just left my position right there and then. When they fire you, it's not like they give you any notice. I generally want to know, because I have honestly no clue. Is it because everyone has been conditioned by corporations for decades?