"Hero" is a word that's misused all the time. People who hit baseballs, throw footballs, or lob tennis balls are frequently labeled "heroes," but they are really just paid athletes - not heroes. It would be heroic if an athlete gave up a kidney for someone who needed it knowing that he or she would probably never play ball again without it. You can't be a hero without sacrifice.
If benefiting somebody else results in no cost to you, you're not being heroic. "Hero" is a very special term. For example, although he was damn courageous, Captain Chesley "Sully" Sullenberger (the pilot who landed Flight 1549 in the Hudson River and saved the lives of all 155 passengers and crew aboard) was not a hero. Yes, he ensured that the airplane didn't hit any buildings and he saved a lot of people's lives, but there was nothing for him to sacrifice because he was going down with everyone else. Although he was courageous and kept his head while those around him were losing theirs, the term "hero" should not be applied.
By the same token, a person dealing with treatments for serious medical issues is not a hero either. As brave as a person needs to be when going through something like that, they don't have a choice. There is no sacrifice involved on the behalf of another person.
I was recently watching the movie Act of Valor, which used real military guys to create a dramatic representation of a true story. In one scene, the soldiers are clearing rooms in a building, and one of the guys goes into a room looking left and right, but he forgets to look up. A bad guy perched on the scaffolding pulls the pin out of a grenade and tosses it into the room. The soldier turns around to run out, but he sees his buddies entering that same room. He has a choice to make: He can either run and see how far he can make it before the grenade explodes, or he can stay and protect his fellow soldiers. To my shock and horror, he threw his body on the grenade, thereby taking the full force with his body. It wasn't pretty. His buddies then shot the bad guy.
That was the part of the movie I remember most. This guy had a choice to make a sacrifice, and he did. That was a heroic act. He could have tried to run or throw himself behind something and let the other guys sink or swim on their own, but he chose to sacrifice himself.
I remember back when our country first entered Iraq, a young soldier did the same thing. He was clearing a room, saw a grenade, and threw his body down on it. I remember being so incredibly upset because I was identifying with his mother, knowing and worrying that my kid might be in that same circumstance. It was just terrifying. But I knew his act was heroic - a personal sacrifice for the benefit of others. That "Band of Brothers" mentality which ennobles a person enough to sacrifice themselves for their buddies is a mind-blower.
In my opinion, some of the most blatant acts of heroism ever known were performed by "The Righteous Gentiles." That's what Israel called people who protected Jews from the German "Final Solution" during World War II. These were folks who knew they could die and their children could be tortured and hung in the street as a message to others for what they did, but they risked everything and did it anyway. When you read or see interviews with any of these people, they all say the exact same simple, humble thing: "It was the right thing to do."
I believe "doing the right thing" has a lot to do with how people are brought up. For example, when my boy was growing up, I told him that I didn't care about the zero-violence nonsense at school. I said, "If somebody hits you, or even more importantly, threatens or hits somebody else, I expect you to intervene and we will deal with the principal later."
One day, he came home in trouble. A boy had been picking on another boy at school, and my son punched the bully. I took my son out to dinner and sent my husband to go deal with the principal.
In short, heroism is about making a personal sacrifice for the benefit of others. It's serving others at a cost to you. When those firemen, police officers and other folks looked up and saw the burning buildings on 9/11 with debris falling everywhere and smoke filling every breath, they made the decision to go into the buildings knowing full well that they may never come out again (and a lot of them didn't). That is heroism - not a guy who gets paid a lot of money to make field goals for people's entertainment.