This political tale was published on the groaners listserve a few years ago.

George Dubya Bush went to see the doctor to get the results of his
brain scan.

The doctor says, “Mr. President, I have some bad news for you. First,
we have discovered that your brain has two sides, the left side and
the right side.”

Bush interrupted, “Well, that’s normal, isn’t it? Doesn’t everyone
have two sides to their brain?”

The doctor replied, “Yes, Mr. President, but your brain is very
unusual because on the left side there isn’t anything right, while on
the right side there isn’t anything left!”