Why people stop dreaming?

Why do we end being so miserable? When do we stop dreaming and start acting like real adults, with real worries and real wounds? I cannot imagine life without a smile and life without the sun, be it just deep in my heart. I cannot imagine living next to a man who does not appreciate me the way I am, with goods and bads. I cannot imagine why people stop dreaming for something better, for something good in their lives. It is because life it's so hard we cannot see the good part of it, or just because we were taught to just accept everything that comes along without arguing about it?

Of course, it's a good thing to take life as it is when you cannot change the facts, but it's deplorable when you don't look any further. And I see this "acceptance" every day, when I look at some of my friends, especially to the females: I have a friend and she's so not wanting to see the things in other way then the one she was raise. With all the religious believes that drag her back, with all the social dogmas and all it comes with it. She just can't see herself earning more than 500-700 euros per month, nor doing something out of the ordinary. She just wants to follow a pattern and stick with it. And if she will never dream more than that, it is a fact that actually she'll never have more. And that is so sad. Why do people stop dreaming and start grumbling!? We only have one life and we can make so much out of it. Why don't we take advance of it and just do it? I would like all the people to start look into the mirror and actually realize that this is now, it's happening now and they have NOW the chance to do something. The past is past. The future is something it will come, someday...tomorrow, the day after tomorrow...but THE PRESENT! Oh, the present is it a present! Make the most of it!