This question was thrown out by my friend Miranda the other day on Facebook. My nice and short answer was the following: "Having a family, the girls' smiles, having not to worry about money, enjoying my job, health..."
In fact, I think it is a lot deeper than that. Thinking about this question during the last few days, I believe that, at least for me, there are two levels of happiness: the "would-be" and the "is". The "would-be" is when I'm dreaming about things and situation I guess would make me happy. I sometimes dream of having enough money to own a nice, 5-bedroom house without a mortgage, never have to work again unless I feel like it, spend all the time in the world with my family, travel the world with them, and never have to worry about it.
Luckily, I am realistic enough to know that most likely, this scenario will never happen. But there's still the "realistic" happiness, and yes, I am happy beyond anything I've ever dared dreaming of. I am lucky enough to be married to a wonderful, gentle, and down-to-earth man; we have two healthy, beautiful girls; I have a job I actually enjoy and earn enough money to be comfortable; we live in a very nice 3-bedroom apartment with awesome neighbors; we have a wide circle of acquaintances and friends. And then there are still those little moments that make me stop in the tracks and smile, most of them involve the girls doing something absolutely adorable, and my heart feels as if it wants to break through my chest.
Yes, I am happy with my life, even without all those "would-be's". Thanks, Miranda, for pushing me in this direction!