How nice it would be

How nice it would be to have enough imagination to live in a dream world.

Both fantasy and imagination concern unrealities; but while the unrealities of fantasy penetrate and pollute the world, those of the imagination exist in a world of their own, in which we wonder freely and in full knowledge of the really real.

Imagination, an unimaginative person once wrote, is what happens when a drunk looses his watch and has to get drunk again to find it.
Although fantasy and make-believe flourish in childhood they rapidly atrophy as one is moulded to fit the adult's grey consensus of reality.
A child, out on a walk with his mother, suddenly points and cries out, "Look a purple cow".
The mother perhaps rather tired and domestically harassed, snaps: "Don't be silly" And then delivers the crunch line:" There's no such thing as purple cows".

So the child, a vagabond in the backwoods of rationality, is brought up to see the world in the prosaic terms of grown-ups and eventually forgets it ever saw a purple cow.
Now purple cows walk around unseen by anyone.