That's putting it lightly. I consider myself a fairly well conditioned athlete, but if I don't pace myself I can definitely gas within 5 minutes. And thats the thing about real fights -- the adrenaline dump! You burn through energy like a torch through newspaper. The average guy will have like 30 seconds of fury -- give or take -- after which his intensity will start to fade. For all of the training I do, I think I could only go 100 percent balls to the wall for 2-3 minutes before fading, but that's still a huge advantage.
And having the cardio to run away is SUUUCH a good point. I didn't even think of that, but that's so true. I find it so ironic that the same self defense enthusiasts (thats what i'm calling them, since the vast majority haven't even been in real situations) will say things like "its about survival on the mean streets. I'll eye gouge him then run away!" will also say "cardio doesn't matter. there aren't rounds on the streets" in the same breath.
Id rep, but apparently I need to spread some more around first.
Cardio is a strange thing...I can spar and roll for a decent amount of time, but when the fights on and the adrenaline is raging I gas much quicker. Pro fighters (with the exception of Lesnar and Carwin), learn how to keep a cool head and pace their adrenaline.