There is a thin line, separating between a fantasy and a dream.
A dream is a positive force. Anyone who ever wanted to be a successful person should have it. By dreaming our future, our brain, somehow, triggered the subconscious mind thus like an automatic machine, our actions was set to achieve the goal: realizing the dream. And, yes of course, we never said "realizing our fantasy".
Or you may say " i had realized my fantasy " whenever your goal-of-my-life is achieved, but the meaning it bears is totally different.
It is not wrong to dream. Even day dreaming is good for us. Remember the tale of Mat Jenin the day dreamer. He is an example of a great dreamer: dare to dream for the impossible. If we never dared to dream, how could we ever come close to our goal-of-my-life?
As dream is a positive force, fantasy, on the other hand, is a negative force. Kinda ying and yang thing. Black and white.
In order to take refuge from the cruel and not so perfect world, the mind itself had conjured a sanctuary that is, fantasy. In a world of fantasy, you can shape the world that you want - who's your girlfriend, what you are, etc. etc. - and nobody ever bother about it.
Nevertheless, always be careful. Fantasy is addictive. It will overpowering the fantasizer, taking him or her into a world that never was. Drug addicts are example of those who let fantasy to overcome the reality and choose to stay in fantasized dimension. Thus, whoever let fantasy to occupy most of his or her mind and put aside reality - the not so perfect world, full of sadness, sorrow, war, etc. etc. - is very much alike with a drug addict.
Animations, cartoon, anime, video games, dramas and movies are mostly fantasies made into the real world. To ease our tense, we watched them. And for a brief moment we forgot the real world. But what will happen if our mind deceived and we can't tell the difference between reality and fantasy?
(Yes, our mind can be easily deceived. Magicians, they are the masters of deceiving the mind and they knew how easy to fool our mind.)
Take a child and let him watch spiderman trilogy. After that, he will be jumping here and there insistently and try to cling to a vertical wall. There's even a case where a child jump off from the balcony straight downward thinking that spider web will come out from his hands. Thank god, the child survive the fall. This, give a clear picture of what will happen when the mind failed to differentiate a reality and a fantasy.
Same things happen not only to child. All of those love and couples dramas really had gave an effect to people's way of thinking with all of those happily ever after endings, when actually in real world, happy ever after without any single argument is virtually impossible. And this may be a possible explanation why the number of divorce case is increasing: the inability to differ fantasy from reality.
Don't choose to live in fantasy. Never refuse to live in the cruel real world. Start reducing your time in front of television and start living for real.