Slay the dragon. Rescue the princess. Two of the most quintessential acts of manliness ever envisioned.
Historically, these idealized, heroic feats are first combined in the legend of Perseus. (You know, that brave, Greek warrior who literally swooped out of the sky and rescued Andromeda from a sea serpent? From Clash of the Titans? With the curly hair? Yeah, him.) Thereafter, the legend of St. George picks up on this same concept and introduces a more Europeanized-version of the dragon. (Same story, less gods, more chivalry.) Lastly, the key elements of the anthropomorphized lizard and the super awesome, unbreakable sword are derived from the tale of Sigurd’s defeat of Fafnir. (The brave Norse warrior didn’t get a princess as a prize, but did he become invincible and permanently gain the ability to talk to birds. Seriously cool.)
But let’s be honest, slaying a big, giant monster is–and mostly likely always has been–simply a metaphor for man’s quest for meaning and power. The dragon is bigger than you, and more powerful than you, but, ah ha! you’ve outsmarted it somehow and stabbed it in the heart. Who’s the big man now, scaly? Oh, and getting to marry a beautiful, rich girl as a result? Well, that’s just the icing on the cake. I mean, you don’t even have to ask her out on a date after an ordeal like that, do you? By all rights, saving a damsel’s life seems like it gives you some serious bargaining power in the relationship-game. She’s gotta fall in love with you, right? Immediately, nonetheless.
Sounds perfectly reasonable to me.