I couldn't have agreed more with deedbr's responses. I thought I had something to add to his first response, but now see that he has already come back and added it. What I was going to add was that even the worst player gets dealt good hands from time to time. Of course when they do, it's hard not to pay them off because of all the all the weak hands we've seen them play badly.
I find it's not uncommon to make the call with the best starting hand, only to see it lose when the other guy ends up making two crappy pair. There is some satisfaction in knowing that our read was good, but not nearly enough. So when it comes to situations like this where I would be risking a large amount of chips to call someone's pre-flop shove, I remind myself that not only might I already be behind, but even if I'm ahead, there is always the possibility of being outflopped. What I tell myself is that I simply don't have to. That is, I haven't invested a single chip into the pot yet, and I don't have to.
Remember, with the chip lead, you have the choice of whether to be aggressive, or the option of being patient and waiting for monster hands. Calling a pre-flop all-in for half your stack with K-Q is neither.