I'm actually in the middle of a paper that is due tomorrow right now, but I saw this quote and thought I'd put up a few thoughts on it...
Everything you can imagine is real.
- Pablo Picasso
I honestly believe that in a way this is true. It is real in your head, at the very least, real to you, if you will, but there is a part of me that believes that it is more substantially real as well.
There is a thought in Quantum Physics that some particles don't exist except when we are looking at them (or for them) at which point they do exist.
Clearly our minds do have some sort of connection to (if not some form of control over) the universe in which we live.
And we clearly don't understand completely the universe in which we live, much less rather or not it is the only such universe that there is.
It is completely possible (and perhaps even scientifically plausible) that everything that we imagine does truly exist in some universe, even if not in ours.