Came across this quote today by Stephen Jay Gould, a big-time scientist (formerly; he's dead now, seemingly sadly, though I didn't know the guy), regarding the fact that there seem to have been many failed hominid evolutionary branches, and ours was the one that survived:
"One of the hardest ideas for humans to accept is that we are not the culmination of anything. There is nothing inevitable about our being here. It is part of our vanity as humans that we tend to think of evolution as a process that, in effect, was programmed to produce us."
Well put, SJG.