Why?

Below are some Why questions.  One mentions- an old song --- Jimmy Crack Corn --- Can you give me the words to that?

Also - what was the professors name on Gilligan?

NOw to the Why's-------

Why do doctors leave the room while you change?
They're going to see you naked anyway.


Why do toasters always have a setting that burns the toast to a horrible crisp, which no decent human being would eat?


If Jimmy cracks corn and no one cares, why is there a stupid song about him?


 
If the professor on Gilligan's Island can make a radio out of a coconut, why can't he fix a hole in a boat?