During flight training, instructors will often advise students (sometimes more urgently than others): "Watch Your Attitude!"
If the aircraft's nose is too high or too low (not an exact definition of attitude, but sufficient for this post), it will affect the quality of the journey and how you impact other objects (the goal of which is to obviously land on the ground, safely, on your wheels, in one piece and with a sufficiently low descent rate that you don't bruise your tailbone!). Your personal attitude can also have an affect on how you impact others around you.
A few years ago, while I was writing this book actually, I was flying as a passenger over the Christmas Holidays. I was talking with the lady working behind the counter at the aiport Tim Horton's. There had been lots of delays during this busy holiday season and when I asked if most of the passengers had been cranky, she replied "no, for the most part people have been in pretty good spirits. In fact, most people are usually pretty polite and friendly when they're traveling ... except for pilots. They're all jerks!" She didn't know that I was a pilot.
I'd like to believe that all pilots are not jerks. I'd like to think that what happened was that because pilots (and flight attendants to a certain extent) are generally the people that stand out at airports with a distinctive unifrom, this poor Tim Horton's women got a few bad apples (who were likely jsut having a bad day)and formed a generalized opinion. It's difficult to distinguish between lawyers, doctors, teachers, steel workers, bus drivers etc. when as passengers, they're all dressed the same.
I'm not sure if this will really negatively impact the public perception of pilots. If he or she flies me safely to my destination, what do I care if their a jerk? But at the same time, I'm of the opinion that being rude to people is not necessary. Being a pilot is hard work and carries a lot of responsibility. You ARE NOT better than someone else simply because you are a pilot. I don't think that everyone has the ability to be a pilot, but I do believe that most people in the world, if they had the financial resources and educational background, would be able to pilot an aircraft.
Being a jerk will not make you a better pilot or a better person.