My thoughts on happiness!
What I'm trying to do is to live happy and living right now, living in the moment and not think too much about the past. If you have too much trouble and regrets, I will not say that you are completely happy. Maybe I'm pulling apart the word happy, but I think the word happy is a very wide term that tell a lot. It is important to lay out your problems and fix them, instead of lying in bed before you sleep and think about them. Most problems can not be solved by thinking on them. If you are regretting something, it does not help going around and think about it. Words like "I should really have done this and that"and "regret", is perhaps occured because of this. People can not put things behind them, they do not put their problems on the table and think too much about the past.
You can't change the past!As Gandhi said, "you should live every day like it was your last" is good to live happily.One should do what you want, you may not be very happy if you go around and do things you do not like. Would you like to travel somewhere in the world, go there before it's too late. Are you thinking: "oh, there I want to go!", then do it! I try my best to live a bit like this and not thinking so much about the past and the future but I live now and do what I want to.