A little boy goes to the doctor and tells him, “I’m smart Doc!”
The doctor says, “Really?” He then points to the boys foot and says, “What’s that?”
“That’s my foot.”
“Very good,” says the Doc. “What’s that?” he asks, pointing to the boys knee.
“That’s my knee.”
“Excellent.”
“Now, what’s that?” he asks, pointing to the boys elbow.
“My elbow.”
“Wow. How do you know all this stuff?”
” Kidneys Doc, kidneys,” the boy says touching his head.