Feeding the Pig

A city boy is taking a drive through the country when suddenly he sees something that 
totally confuses him: A farmer is standing outside under an apple tree with a pig in 
his arms. Every few minutes he holds the pig up; the pig bites an apple from the tree; 
the farmer holds the pig while it chews and swallows; and then he lifts the pig up again. 
After watching this repeated for some time, the city boy rolls down his window and calls 
out, "Can I ask you a question?" 

"Sure." 

"What are you DOING?" 

"Feeding my pig," says the farmer calmly. 

"Why don't you just put the pig down and shake the tree until a bunch of apples fall down 
for it? Wouldn't that save a lot of time?" 

"Time?" says the farmer. "Son, this pig's got nothing BUT time."