I think that happiness is a personal choice, in that you can choose to see something in a positive or negative light. Say you've had a really rough day at work, and on your way home you get stuck in traffic. Do you get grumpy and think your day is even worse, or do you relax, turn up your music and enjoy having some time to yourself. This may not be your optimal idea of "me time", and maybe it’s not something you’re really going to be happy about, but is it going to ruin your day? This is where you have to decide whether or not you want to be positive or negative about something. It might sound hard, and at first it might be, but it really is as simple as just saying, “Hey, this is not the end of the world, and it’s not going to ruin my day, so relax.” The more positive you are in situations like this, the easier I think it is to be happy in the long run.