I spent part of my day today touring a museum I had seen only a few weeks ago for the first time.

I wanted to show a friend of mine what real heroism looks like. Truth is, I cannot get enough of those tales of valor and gallantry.

The National Medal of Honor Museum sits across the highway from AT&T Stadium. The exhibit seems inexhaustible. I went through it a few months ago with my brother-in-law. The museum floor seemed to contain even more exhibits today than it did earlier this year.

I have learned something important about the Medal of Honor recipients, which is that they are motivated to act above and beyond the call by a single factor: their own mortality.

Don’t misunderstand me on this. They are driven by the love they have for their brothers in arms. I get that. As President Obama noted during a Medal of Honor presentation he conducted near the end of his presidency, citing Scripture that tells us that “there’s no greater love than that of a man willing to die for his friends.”

These men all acted as well out of their own sense of mortality. So many of them have recalled the moment they responded with extraordinary heroism that in the moment, they were certain they were going to die, so given that belief they acted like the heroes they became.

They are immortalized in a fabulous exhibit in Arlington, Texas. I will return again and again.