A lecture about English
A linguistics professor was lecturing to his English class one day. "In English," he said, "A double negative forms a positive. In some languages, though, such as Russian, a double negative is still a negative. However, there is no language wherein a double positive can form a negative."

A voice from the back of the room piped up, "Yeah, right."

Bad Couch Trip
I've been feeling down for so long that I finally decided to
seek the aid of a psychiatrist.

I went there, laid on the couch, spilled my guts then waited
for the profound wisdom of the psychiatrist to make me feel
better.

The psychiatrist asked me a few questions, took some notes
then sat thinking in silence for a few minutes with a puzzled
look on his face.

Suddenly, he looked up with an expression of delight and
said, "Ummmmm, I think your problem is low self-esteem. It is
very common among losers."