Of course, stereotypes are a bad thing in general. Even those based on some kind of truth usually fail miserably when applied to a large group of people.
For some reason, the stereotype applied to Polish people tends to deal with their supposed lack of intelligence. This is obviously untrue, however it does make for some entertaining jokes. However, the Polish contributions to the world in intellectual fields should not be overlooked. Here are two examples of outstanding Poles that I can think of off the top of my head.
And yes, to answer your question, I am of Polish descent and made a vow upon my grandfather's deathbed to defend the honor and dignity of the Polish people. Okay, so that last sentence wasn't very true. In fact, my grandfather is still alive. But I am of mostly Polish descent.
- Nikolai Copernicus - Copernicus was the first to actually prove that the Earth was not the center of our universe. This was a great breakthrough in astronomy, although it did greatly upset the Catholic Church.
- Marian Rejewski - This man actually quite possibly saved the entire of Western Civilization from a man by the name of Adolf Hitler. Rejewski was the man who cracked the original Enigma cipher, which almost everyone thought was impossible. "But I though Alan Turing did that!", right? Turing cracked the modified Enigma cipher, using techniques largely based upon Rejewski's work. This is not to detract from Turing's own work. I think that Alan Turing is one of the most signifigant and brilliant minds of the twentieth century.