Aren't they? I mean...you can just close your eyes and imagine. We're just not in the kind of state that allows those thoughts to be actively projected in the retina. You might think I'm just talking jibberish. But what really keeps us from dreaming in mid-day?

I like my dreams. They are so real, and so unreal sometimes. Filled with color, sound and taste. Many of the times i don't even realize I am dreaming, so I got scared in a few ocasions. Falling in a deep void is not very nice. But they say you have to fall, you reconect to your body that way, and thinking and wishing to stop the fall may cause your death. Could be true, i just instructed my subconscious mind not to be affraid of the fall, and now I know when I'm dreaming or not. Perception is relative they say. Percepting a dream as a dream is in fact very easy, so the hell with relativity.

Sometimes i have erotic fantasies. Those are my most realistic dreams. I have one sense that in all other dreams is inactive for some reason. I can touch and feel perfectly. It is weird isn't it? 

So what really prevents us from dreaming whenever we want? Could be our natural atmosphere? Just like the sun gave Superman powers that he didn't have on his own planet? Maybe so. Many experts say that by concentrating on something during the day, we have a very good chance to dream about it at night. Some of them say it with certitude, especially cause we don't remember most of our dreams. So, what shall we think about? Anything, really. As long as you want to dream about it ;)