"Our actions don’t often make sense."

If you consider that everything everyone says or does is designed to benefit them in some way, even if the benefit is emotional, it's usually pretty easy to figure out unless a lot of what is going on is secret. And that is why people tend to become less admirable or heroic as time passes by. People write memoirs and scholars dig through their dirty laundry. Books and other medium like film portray them in less than heroic light. People begin to realize that even if they helped a lot of other people, everything the hero did was out of the pursuit of their self-interests.

The first hero ever in a story, was the Greek warrior Achilles in the Illiad, and he was totally prideful and self-interested. He was a hero solely because he was the total badass that was stacking dead Trojans, including Hector, like firewood. That's a hero in the classic sense, focusing only on what they were famous for, and leaving out the flawed human part.