The Happiness Hotel is both a song and a place in the Muppet's Movie "The Great Muppet Caper". The place is a wreck, condemned, full of vermin and well not a place to live in. But everyone living there is happy.
The happiness comes not from their surroundings, but from their positive attitude to life. What one doesn't have, one doesn't have. What one has, make the most of. They were happy because they were not counting on being GIVEN happiness (more money, prettier clothes, more respect etc.), but they TOOK happiness for themselves. Their joy was inner driven. A way of looking at the world which is in some ways like the child looks at the world, where the sunshine and rain, a rose and a dandelion are of great value.
No I'm not suggesting we all move into a dilapidated, vermin ridden hotel. But the general attitude, that we need to look at what we have, that we need to appreciate what we are given. We need to realize that WE not any outside force is the source of joy in our life.
When you are feeling down and sad try and look and find what is there already for you to enjoy.
For a Torah view on the subject go here:
Happiness and Personal Growth
(by the way, This site, SIMPLE TO REMEMBER is fantastic for Jewish audios and articles.)