Why do we value something only if we can't have it, or have lost it? Why is it so difficult for us to appreciate and be thankful for what we do have? We have this tendency to set our eyes on something we think we want, need or like, and then decide that that is the only thing that will make us happy.
I've discovered that you don't always get what you want. You generally get something completely different. When I wanted to be a journalist, I set out to be a Mathematician. And I was happy being one. When I had my heart set on Mathematics, I landed up in the software industry. And I am happy here too. There's no telling if I'd have been any more or less happy if I'd got what I originally thought I wanted. I mean, writing makes me really happy, but only because I write exactly when I want to, as much as I want to, and about what I want to write about. Writing in a constrained environment may not have kept me as happy as my current job keeps me.
There are other areas in life where this is equally applicable. But I don't feel like talking about them right now. I just feel like telling everyone who's reading this, and myself, to be happy with whatever cards life deals you. Appreciate the good things in your life. Don't hang on to thoughts of the "If only..." kind that make you upset. Not to say that you should let go of your dreams. Most certainly not. Go after them, by all means. But know where to draw the line. Know how to distinguish between what you really need or want and what you can be happy without, if only you put your mind to it.