Something I've recently realized, what if Wernher actually is originally from Kerbin?
My explanation for how this might actually be true is this: The Kerbulans are extremely warlike, so much that it is probably built into their instincts, but Wernher seems to be pacifist, like the Kerbals, and to generally have a lot more in common with Kerbals than with Kerbulans, Therefore he probably is a Kerbal, and he somehow wound up on Kerbulus, probably when he was too young to remember being from Kerbin, but like the Kerbulan's warlikeness I'm going to assume that Kerbals probably have their peacefulness built into their instincts, therefore resulting in Wernher remaining peaceful despite living amongst a society of warlike barbarians.
However, that leaves the question of how did he get to Kerbulus? Monoliths? An early rocket experiment that went terribly, terribly wrong? We may never know...
*Puts on tinfoil hat*