Yes, exactly. I've always wondered why for example, veterans always denies that they are, and I thought they were just being modest. I've also noticed heroic civilians do the same thing.
I've come to realize that no, they were just telling the truth in how they've felt.
In the heat of battle, when your comrade(s) is about to get shot, the only thing that comes to mind is to save him. At that point, you just don't want your brothers who've shared the same experiences through basic, military life, and in combat, die.
Often, those who've become heroes weren't looking for the opportunity. Opportunity finds them. And when the moment comes, when "Fight or Flight" (Faint or Freeze in between) kicks in, it is virtually automatic.
"After the Fact", if you've recovered sufficiently from that traumatic experience (depending on what danger you've experiened), you realized... "Wait... I'm no hero.... it's just something I just had to do. I didn't have a choice."