Since I am studying Beowulf with my English 12 students, I looked for resources to help them. In many of these resources, the topic of what a hero is or what a hero should be features as a prominent them.
This year, when I brought up heroes, they did not have 9/11 on their minds, but rather had Heroes, the television show on their minds.
Personally, I believe becoming a hero is a matter of opportunity: something wild happens and the hero steps up. This is a matter of opportunity because the true hero has wired him/herself by so grooming his or her character that doing the right thing is automatic. The hero acts on autopilot.
I hope that that would be me in a tough situation.