"Why not get a job?" joke

Father: Why don't you get yourself a job?
Son: Why?

Father: So you could earn some money.

Son: Why?

Father: So you could put some money in a bank and earn interest.

Son: Why?

Father: So that when you're old you can use the money in your bank account. ..and you would never have to work again.

Son: I'm not working now.