Anger is not passion. I've heard it said more than once. "I'm angry because I'm passionate about this!" It's not necessarily true. You might be angry if someone runs over your toe with their car, but you're not going to be passionate about your toe unless something you ARE passionate about is related to your toe - dancing, for example. Now, you can be angry about things that you are passionate about, but anger is not equivalent to passion.

Rudeness is not passion. Another one I've heard. "I'm sorry if my words are harsh/I'm sorry if I sound rude, but it's just because I'm so passionate about this." Honesty is different from rudeness, and rudeness is not passion. Not only is being rude one of the worst ways to get a point across, but no one will hear the good parts of what anyone has to say if what they have to say is sprinkled through with insults. Their concentration will immediately be on the fact that they have been insulted, and how they should defend themselves.

Extensive knowledge is not passion. Someone can know a whole lot about a topic, but still not be passionate about it. Granted, it's very likely that people ALSO know a lot about the things they are passionate about - but we aren't passionate about everything we are knowledgeable of.

Now, all of these things can be symptoms of passion, but they are not equivalent to it.