What’s the difference between a general practitioner and a specialist? One treats what you have, the other thinks you have what he treats.
A woman takes her son to the doctor's and tells the doctor that he thinks he's a chicken. The doctor asks, "How long has he been like this?" The woman replies, "Three years." The doctor exclaims, "Three years! Why didn't you bring him in sooner?" The woman says, "We needed the eggs."