[omegaham]

A more obvious setup to the joke is

"Is there a doctor on this plane???"

"Well yes, but I defended my thesis in comparative literature..."

[rkomorn]

Ugh. Of course. That makes a lot of sense.

Didn't come anywhere close to getting it on my own though!

[linsomniac]

Right, but what makes it work for me is that you have to bring the setup to the table. I think The Far Side is similar in a lot of its humor.