Because what you see is what you get, obviously.

Customer to me: Boyfriend?

Me: No.....

Boss: Oh our Ashley doesn't do boyfriends.... *laughs*

Me:...er what?

Boss to Customer: She only has ever got drunk twice in her life.

Me: Erm.....

Me actually thinking sarcastically: Oh yes I'm a typical Spinster who doesn't have a social life.

I restrain myself from throwing something particularly hard at him and loosing my job.