I ask any American, what happened in 1492. They will tell me, 'well Columbus sailed in 1492' and that is correct, he did, but that is not the only thing that happened in 1492. In 1492, England and France signed a peace treaty. In 1492 the Borgias took over the Papacy. In 1492 Lorenzo de Medici, the richest man in the world, died. Okay. A lot of things happened. If there had been newspapers in 1492, which there weren't, but if it had, those would have been the headlines. Not this Italian weaver's son taking a bunch of ships and sailing off to nowhere.
Okay, but, Columbus is what we remember. Not the Borgias taking over the papacy. Okay? Well, 500 years from now, people are not going to remember which faction came out on top in Iraq. Or Syria. Or whatever. And who was in and who was out. And, you know... but, they will remember what we do to make their civilization possible.Okay? So this is the most important thing we could do.
The entire clip from Dr. Zubrin's talk is worthwhile, but I especially love the above segment. I haven't fact checked him or anything he said, I don't know if those things did happen in 1492. I have no reason to not believe him, but it's the Internet so giving a bit of warning. But his answer on why going to Mars is so important is just excellent.