I agree with this generally. For most people I know in happy marriages it's not because they figured out exactly what they wanted and found "the one" -- as much as they love their partners there are probably a lot of people they would have been happy with.
Yes, if you're not religious it's actually pretty ridiculous to believe that there is a "perfect person" for you. To paraphrase The Office, if that were true they're probably in China or India anyway so most of the readers here are out of luck.
I know this is tongue-in-cheek, but I still think it's not the right point of view. A lot of the compatibility in a long term relationship stems from shared values, experiences, interests and culture. So I think your pool of potential "perfect people" is a lot closer to home than that.
