Life and death

I don't know why I am thinking about life and death a lot these days. May be I am dealing with mid life crisis. I am trying to understand the meaning of life, what is really life? why we are here? I feel like every day of life is like you are taken to a party that you did not want to go but your friends took you, now you can either sit in a corner and wait for time to pass by so you go home or you can mingle with people, drink, eat and have fun. How many of days of our lives we act like first scenario just are passive and wait for time to pass by and how many days we act like second scenario, we have fun and enjoy it. I think our daily life can be good, bad or just regular without any high lights. How many happy days of your life do you remember? Are there most of the days just OK without any highlight?
I read somewhere once that happiness is wanting what you have not what you do not have. May be that is true!
I become sad when I remember the dreams that I could not follow, things that I were capable of doing but did not try them. May be my life would be worse if I had followed some of those dreams may be not. You never know what is really best for you.
I at least know something, I have a good life with two beautiful kids that I adore and love to death!
I have to thank god for all he gave me and all he did not give me, because may they were not good for me any way!