Why do we want what we cant have reddit

Why do we all want what we can't have? What can we do about it? from AskReddit

Why am I only interested in guys I can't attain, or who were once interested in me and aren't anymore, and how do I change it? from AskWomen

ELI5: Why do we always want the things we can't have? And sometimes stop wanting them the second we can have them? from explainlikeimfive

What drives our "grass is greener" mentality? Can we ever truly live without want?

Is there a psychological or evolutionary predisposition to desire things we can't have, even if on a logical and intellectual level we know we can't ever have them? Why is it so?

Why do we want what we can't have? from AskMen

A two years I had fallen head over heels for a girl in my class but she wasn't interested. At the time I was quite disappointed but I later realized that perhaps that relationship is entirely feasible. I had moved since and focused all my attention on other aspects of my life. However I now find myself thinking of her more and more and wishing that it would have turned out differently. I know that the girl and I can definitely not be together. Yet I find myself wanting spend more and more time with her.

For those of you who are curious, we cannot be together because she is muslim and I am not. There other factors as well such as our fundamental objectives in life do not match.

Can someone help me figure out how to handle this?