I could make the sky blue and pumpkins orange. I could make silly words, like 'snorkel', and silly species, like monkeys. I could make flowers beautiful, and babies cute. I could make you read these words, right now.
Of course it would be very difficult to prove this to anyone, including myself. You see, once I make the sky blue, it has always been that way. Even if I made something really crazy or unlikely, that would just be the way things are. You could challenge me, saying, "Change the calendar, so that one of the months has 28 days," but once I do, it was already like that (and of course there would be some reason), and the challenge would be something else.
It's tempting to think, "There's no way to prove it one way or the other, so it doesn't matter," but that would be saying that the truth does not matter. It would mean that we are closing off all aspects of reality that our mind can not understand or measure.
I'm not telling you to abandon measurement or believe in these abilities -- that would be foolish. Instead, simply ponder the possibilities. This is not about belief -- it's about disbelief. Reality is larger than we can possibly comprehend.
Are you certain of something? If so, is it possible that you aren't seeing the big picture? Perhaps you would change your mind if your understanding were a little broader.
As you consider this, you may begin to sense gaps in your reality. If certainty is gone, then nothing is definitely impossible. Maybe invention is a simple matter of observing what has always existed, and change happens when you notice parts of your self that were there all along. Maybe big ideas are only impractical for those who lack vision and imagination.