Intelligence and physical fitness...you may be wondering if that is a weapon, but that's okay because I'll go off on a semi-rant and explain the almost un-relevantness of this theory.
Hrm...Hrm! (gather around, I'm about to tell you the Epic of the Future)
The year is a long time in the near future and the planet is quiet. We journey through what was once a thriving city to find empty, lifeless streets. Although, hold on a second...there appears to be movement. A strange looking machine is "running", trips, gets back up, and then starts running again. We attempt to follow it, but it darts into a crumbling apartment building. Carefully, we open the door. It's dark. But, as we peer around the corner, we notice a glow projecting on the wall. Creeping around the corner, a silhouette lays down staring at the color screen. We move up to it and are surprised to find it is strangely... human. The creature is dreadfully thin, severely atrophied, and seemingly unresponsive to external stimuli. You look down and notice this pitiful thing has defecated itself and is starving. It reaches up to grab you and you smack it's hand back as you start to leave. Seconds later, a swarm of the things begin to gradually run after us. Having lost most of their muscle after generations of de-evolution and genetic decay, the creatures seem to tire out and die. You also note that they seem to be harmed by the sun light as they probably have not been in the sun for many years.
(By now, I'm sure you know what I'm getting at, but I'll just finish off the story if you were actually interested in my babble)
We turn the corner and use our geometry skills (which you probably thought would never come in handy D_D) to enter a home through a window, find a square (triangles don't fit in the square hole, duh) to plug the window and keep the zombie people out, and live the rest of your life forever alone

Not the ending you were expecting, right?