IMO, the real "gunners" are not the people who study all the time, they are the people who do their best to tear you down and try to make you doubt yourself. Usually they do this by talking about how much they supposedly drank, or posting a picture of a party they went to, or talking about some DJ at a nightclub.
When in reality they're sitting at home with their lecture notes and BRS and First Aid for as long as they possibly can.
One thing I've learned is that you can't trust anyone, and that EVERYONE is always frontin' and talking a big game.
Other things that bug me:
1) People who claim they are dead set on going into Neurosurgery. Honestly, I wouldn't care except that at least 30% of the school claims this, which makes me wonder what on earth is going on here. Who knew Derek Shepard from Grey's Anatomy could influence so many people?
2) Professors who make it clear that they don't give a crap about you learning or even remembering anything, and they just want you to "memorize [in their words]" particular facts of information, spit it out, and forget about it 20 minutes after leaving the exam. I mean, I appreciate their candor, but it still leaves a bad taste in my mouth.