My philosophy teacher is sometimes quite funny. We were discussing Marx and what he would call private property, as opposed to personal property, and my teacher used this as an example of personal property:

"If it's just money that I've shoved into my mattress [as opposed to it being invested in stuff], it's just a very expensive mattress."

Later on in the class, he was defining a capitalist as someone who makes enough money off of their private property to live. Someone sitting next to me got a bit confused:

"So the monkey-grinder man is a capitalist?"

The example was that the monkey and organ an organ-grinder owns are his private property, and if he can a living just doing organ-grinding, he's a capitalist.

People are weird, strange, funny things.