Does life has any real reason that makes it worth living?

That´s the point, what could be a good reason? Dreams, things I like, family, etc., they are not really important if I compare them to everything else in universe. If that is the case, excistance itself is nothing, each life is even less, and living is useless.

What I want to find is something that could change that, and to know what means to be happy (and happiness is not in anything I´ve got or felt), because I see that people do things, find other peple, etc., to feel that way, and if there is not a good reason for living, why people tries to "be happy", if is imposible to reach a true state of happines?

I can´t understand, the real motivation for life, the reason why the first living beings holded to life besides they where doomed to extintion, or what led us to think in ourselves as a superior specie and think we deserve everything. That´s the reason I want to find.

Have you ever read into quantum theory? Specifically I'm talking about the works of Erwin Schrödinger, Richard Feynman, Heisenberg or even bits of Hawking's research. Having a platform to observe the universe nearly collapses the alternate histories of the Universe into a comprehensible model. It eliminates superpostions and keeps reality, well, real. Think of it on the must basic levels and yiu can easily conclude that your prospective keeps the entire Universe stable.Every being capable of observing quantitatively is, in a sense, responsible for maintaining the stability and coherence of the slice of the cosmos we can observe.

Edit: I know I'm using physics to answer a philosophical question, but as Stephen Hawking said, "Philosophy is dead".

Basically, it's how you've lived all these years that makes you the type of person you are now. From this, you set objectives you aim to achieve before your life will end. And once you've achieved every goal you've set, only then you can say that life is worth living.

Real reasons? Humanity will probably go extinct as some time, somehow, life is too fragile, someday the Sun will either turn into a black hole or expand and swallow the earth. Or maybe we nuke each other to extinction.
The holy lands which were shed blood for will inevitably disapear, our left-behind culture would disapear.

Our sons and daughters will die and our grandchildren would remain, and if they are successful to survive, they will leave great-grandchildren, who will die too anyway. But we left a piece of ourself, our genes, a remnant of ourselves in our great-grandchildren, and we lived to meet someone we loved. Come to think of it, somewhere in your family tree, you have a characteristic of a very far relative, who lived to pass on his genes, and his/her gene pattern is inside you, a part of who you are. Be proud of that, and don't forget it. Acknowledging that means that even though they are gone, a piece of them remains alive, a proof of their existance on the face of the Earth. It might be a behavior, or a psysical appearace, a hint in your hair color, the shape of your earlobes, a small trace of them would remain and appear (or be ressesive and instead pass into your children). That thought makes me smile.

Even if we can't pass our genes, we can still leave an improvement in our culture, adopt and raise an individual with our thoughts, and contribute to the overall survival of our species.

So why live? Because it's part of our instinct. It's a truly marvelous part of evolution. We live because our predecessor species lived and adapted, in honor for them, we should do the same. To survive and improve our species.

Thus, no matter how depressed you are, no matter the verbal ass-whooping you recieve, no matter a violent barrage you feel, you must stay alive. Staying alive is the only way to go, build some character and don't give up no matter how "pathetic" you may be considered.