Well, would you like to take a shot at explaining it?

Conversation between self and Rusty this morning, in re our friend Roy, who happily ran a coffee shop back in the day until his partner cheated him out of his half of the investment and forced the business to close (or something more or less along those lines), and who is I would suppose in his mid-fifties:

RUSTY: Dad, do you remember Mr. Roy?

DAD: Of course I do.

RUSTY: He works in a computer store now.

DAD: Yes, I know.

RUSTY: I wish he still worked in a coffee shop. We should get him a job in the coffee shop [meaning Java Dave's, at which I am so regular a customer, and Kinya so regular a barista, that I think perhaps Rusty thinks I own the joint].

DAD: [chuckles] Rusty, I don't think Mr. Roy liked working in a coffee shop so much as he liked owning the coffee shop -- I don't think he'd like working in somebody else's coffee shop.

RUSTY: Oh, yeah. [Thinks a moment] Well, maybe someday I'll be rich and I can buy him his own coffee shop... [meditatively] if he's still alive.

DAD: [can't talk and laugh at the same time]

RUSTY: [plaintively] Dad, what's so funny?

Now, Gentle Reader, would you like to take a whack at explaining to Rusty why what he said is funny? 'Cause Rusty's dad doesn't know where to start, exactly.