The difference between potentially and realistically

A young boy went up to his father and asked him, "Dad, what is the difference between potentially and realistically?"
The father thought for a moment, then answered, "Go ask your mother if she would sleep with Brad Pitt for a million dollars." Then ask your sister if she would sleep with Brad Pitt for a million dollars, and then, ask your brother if he'd sleep with Brad Pitt for a million dollars. Come back and tell me what you learn from that."

So the boy went to his mother and asked, "Would you sleep with Brad Pitt for a million dollars?" The mother replied, "Of course I would! We could really use that money to fix up the house and send you kids to a great University!"

The boy then went to his sister and asked," Would you sleep with Brad Pitt for a million dollars?" The girl replied, "Oh my God! I LOVE Brad Pitt. I would sleep with him in a heartbeat, are you nuts?!?!?"

The boy then went to his brother and asked, "Would you sleep with Brad Pitt for a million dollars?" "Of course," the brother replied. "Do you know how much a million bucks would buy?"

The boy pondered the answers for a few days, then went back to his dad.

His father asked him, "Did you find out the difference between potentially and realistically?"

The boy replied, "Yes... Potentially, you and I are sitting on Three Million Dollars.............. but Realistically,......... we're living with two Sluts and a Queer."