for me i think happiness comes when ur realation with GOD is so strong and have deep faith on HIM. happiness also could be found in simple things u might do and give u happiness. for example when i play games that i like it really gives me nice feeling and also make u forget ur problems or sadness by consentrating on the game only and even if just for a little time. but this will do good to u and also its a practicing for ur brain
. there are also some important reasons for happiness like good family bounds, success in life and work, and when u feel that u r making a diffrence in your life and others life aswell.