And then it dawned on me. John McCain doesn't know what a condom is for. He doesn't, for example, know that it can prevent the spread of AIDS and many other sexually transmitted diseases. He left his first wife by courting another woman while still married. Knowing what we know about the sexual habits of soldiers under fire (the millennia long tradition of the "camp follower") and the sexual habits of politicians (nearly every President has kept a mistress or twelve), I think it's safe to say that John McCain has had a few indiscretions.
I'm suggesting that John McCain has had sexual encounters with potentially unidentifiable partners. By his own words, he doesn't know what condoms are for. Through that lens, I think we can clearly identify what is actually wrong with John McCain. His brain is being slowly reduced to cottage cheese through the ravages of tertiary syphilis. Suddenly, it all makes sense.