Reality and fantasy do not differ as much as one would expect. The line between the two is most likely a very thin line and we're all probably dancing in between it, every now and then. The line is where you decide it to be; it exists only in the human mind and it varies with the individual and the age. It all comes down to perception and belief. Imagination is the license that allows us to play with conventions and re-define them, to re-negotiate the parameters of reality.
Escaping from reality is positively exciting and beautiful. At times, we get overstimulated by our fantasies and we start to act them out. Why not? I like to bend reality. Fantasy is not harmful. I believe fantasy reduces stress. It all depends which side are you on. What do you choose, the ordinary or the extraordinary?