Do you find yourself focusing on the negative aspects of your life rather than the positive ones? If the answer is yes, don't feel bad. It's human nature to pay more attention to what's wrong. If only I could lose those 10 pounds... If only I made more money... If only he would propose... then I would be happy. The problem with this type of thinking is that happiness is not based on conditions; it's a state of being.
I'll admit it has taken me some time to learn to live in a state of gratitude, but I'm there now--and so much happier because of it.