A hero (or heroine if they're women) is someone who looks beyond himself (or herself) to help others. They move beyond their own lives to touch the lives of other people. They make the decision - whether it's consciously or subconsciously - that they're going to do what others can't/won't/are afraid to do to help others. This is what makes a hero.
There are reluctant heroes, especially in fantasy and science fiction. The first reluctant hero to cross my mind is Garion out of David Eddings' Belgariad series. By the time of the second series, he's kind of gotten used to the whole hero thing. But in the first series, he didn't want to be a hero and was actually very whiny about it too. In Ender's Game, Ender was a reluctant hero. He didn't want anything to do with fighting and ended up helping save the universe from a terrible threat. I'm not as familiar with reluctant heroines, but if there are any out there please let me know. I'd like to read more books where the hero/heroine AREN'T aware of their destiny or are trying to fight it.
My protagonists - my "heroes" and "heroines" - are all hopelessly flawed individuals who end up fighting those flaws in order to help others. In a way, they also help themselves because they're forced to rise above who they are to accomplish what they need to.
So what are your thoughts on heroes/heroines?
