What You and I Once "Had"

When people say to me "Oh, we're so happy together, we're so in love - yeah, we really think this is forever" or some word vomit like this I sit there, try my hardest to not stick my finger down my throat like I am doing (in homage to Ally McBeal) in my head.
I paint on a smile thinking "YOU ARE NOT!! You're just not. I'm sorry, but you -- you, umm... wow, do you even know you're lying?".
Then I think I must actually frown, I suppose some imagine that's because I'm single and I'm having a woah-is-me moment for my poor lonely self, but in reality I'm frowning because it saddens me that eventually what you have will come crashing down and you're fooling yourself. Telling yourself sweet nothings and all the while headed for something that hurts far longer and harder than it ever felt good. It also saddens me because I know I'll end up back there sooner or later; suckered in by someone a little special that I believe will genuinely save me from myself. They won't. They will distract me for awhile with kisses and conversation, which will be nice and hardly something I'll regret when the tears and gauntlets have been thrown. But that distraction will inevitably prove to have been little more than time procrastinating.
See, I don't really know when I got to be so outwardly cynic. I'm not entirely. I do enjoy moments, but I don't like the false ideals we've set for 'relationships'. I am well aware that we have physical needs as humans to hate, desire, lust, cry, feel joy, express needs and wants. But I don't really understand why or when someone set into us that we must spend our lives with one specific person. It's perplexing to me that it should work this way. As adults it should be possible for us to spend time with another person, be honest about how we feel towards that person and be honest when it's over. Not to expect so much from someone who isn't able to know your expectations no matter how much you believe that they should.
People are so intricate that the idea we might ever find the other half to that which is already an entire whole is inane. Everyone seems to spend their whole lives trying to find that someone and then deciding they need to find themselves; over and over again.
I've got money on the fact that there's nothing to be found; and the reason we all spend so much time dwelling on the past and fretting over the future is simply because we can't admit we missed the present, whilst we had our heads amongst the clouds of Preconceived Notions.