Open Question: Has anyone ever stopped paying on their storage unit rental?

If you did what happened? I have one i am behind paying on and got a letter saying they would sell my things to make up for what i sell and what is left over i can have. It says that personal papers and personal effects will not be sold but given back. Not sure what personal effects are or if i will get back certain things i know are not important to anyone but me. I wonder if it depends on the place and people that own it?