IMPORTANT I'm not writing anything special. Everything you are about to see written on this page has very likely already been said by someone, either at the present time or in the past, either in this or in another language either in this or in another form. Everything that had to be said about life has already been said. I'm just writing what i think i've learned from my time on this earth. And I hope for it to help, or for it to be interesting at least. Even a tiny bit.
To live life you need problems. If you have anything you want the moment you want it, then what's the point in being alive? Death gives meaning to life just as much as problems give meaning to happiness. Because for something to be valuable, it also has to be finite. If it wasn't finite, it wouldn't be valuable. And where happiness ends, problems begin. And where problems end, happiness begins.
Of course, you don't get to choose your circumstances. (And, in an hypotetical world where you could: there would be no problems, therefor no happiness.) You don't get to choose the date and time of your birth, the color of your hair, your lineaments, your intelligence, your family's financial situation, your eye's color, and everything else that's assigned by fate at birth. What you get to choose, it's what you do with what you've been handled. That's why envy it's pointless: Envying another's undeserved wealth, or health, or strenght, or intelligence, or happiness, is as nonsensical as saying: "I'm angry at the fact that i was born with 5 fingers per hand, and not 6." You are in your situation not because it's your fault, but because you and them are NOT the same person, have NOT lived through the same experiences, have NOT had the same starting circumstances. You are on your own journey. And if, before being born, you could've had the chance to choose: surely you wouldn't have failed at pleasing yourself. Therefore don't feel bad about things that you didn't (or cannot) choose. Favorable circumstances are bullets for your gun. But in the end the choice to press the trigger it's up to you. And if you're a good shooter: even a single bullet is enough.