There are 2 main things that make us not happy: 1. not accepting the past. 2. fear of the future. One can't change the past, so being angry, having grief, or whatever emotion one has where one is not accepting of the past feeds negative energy; just accept what has happened in the past because it can't be changed. FYI - think of life as a movies that one has a unique view of; nobody else has the view you do, appreciate it and be greatful for the experience. Also, one can't predict/control the future, so spending time being fearful of it also feeds negative energy. Accept that the future will bring exactly what one needs to grow. Be happy by accepting the past and not worrying about the future.