In your whole life, there are some people that will leave marks along the way - the one you first loved, the one who broke your heart, the one that got away, and the one you can't be with.
Who's the one you can't be with? It's the person - for all possible reasons - you really cannot be with. You are meant to meet this person, get to know them, and fall in love with them for their very charming personality. They will sweep you off your feet, take you out on special dates, kiss you when the moment is right, and make your heart skip a beat any time of the day. It all sounds perfect until destiny decides to swoop in and make you realize that hey, both of you can't be together. And let me tell you, there will be a thousand reasons why. Maybe she's married, maybe he's going to be continents away, or maybe both of you are just a drug to each other - gives you a very good high but considered illegal by the public eye.
What's worse is that the mere reason of love for that person will be invalid. It's a kind of "Against All Odds" thing. Or better yet, it's the perfect description of a love asymptote - no matter how you do or see it, both of your paths will never ever cross each other. That happy ending will never come. Sure, you can push your luck with fate and try to keep it going. But at the end, everything will fall into place. You will realize that what ever you do, you two were just never meant be together. Not today, not tomorrow, not ever.
Even if you turn the world upside down, there's not a single chance you'll end up with this person. So to those who love someone that can't be with them - here's to you and your great sense of unrequited love. May you realize in five minutes that your heart deserves someone better - you need to be with the one you’re destined for.