Life's Definition of Reciprocation

I don't understand why when you throw your own self to life thinking that no matter how essential your own being is you'd still believe that life will give you back a million times more of happiness. Thus, you dive in and risk the only priceless thing you have in possession, YOU. Later on, after going through so much tough experiences you will realize that you just got less of what you bargained for. Is it worth it? Maybe. Is it painful? Yes of course. Losing is always painful as much as winning is so sweet. But of the two, losing though no matter how loathsome it may be or how we always try to get away from it, this is what's going to teach us to keep fighting back. The feeling is going to suck, seeing everyone around you succeeding and there you are struggling and uncertain of what's going to happen next stuck right at the end of the line. You feel bitter for others winning and you, though deep inside you know you deserve more is just too helpless to do anything for yourself. Most of the time you just allow yourself to get sucked by depression like it's as if that very thing will come into life and send you back to where you think you should be. This world is unfair. It's going to keep on slapping you with hate, fear and rejection and it would totally pull you to the ground. It will crush your very essence. It hates what makes you feel secured and contented. Despite being around people who cares about you, at the end of it all everything about your story will be written by you and no one else. You will feel alone but you have to accept that to win, you have to make the biggest sacrifice. In this world you have to stay alert and strong or you will ultimately lose this battle.