Imagine ghosts, gods and devils.
Imagine hells and heavens, cities floating in the sky and cities sunken in the sea
Unicorns and centaurs. Witches, warlocks, jinns and banshees.
Angels and harpies. Charms and incantations. Elementals, familiars, demons.
Easy to imagine all of those things: mankind has been imagining them for thousands of years.
Imagine spaceships and the future.
Easy to imagine; the future is really coming and there'll be spaceships in it.
Is there then anything that's really hard to imagine?
Of course there is.
Imagine a piece of matter and yourself inside it, yourself, aware, thinking and therefore knowing you exist, able to move that piece of matter that you're in, to make it sleep or wake, make love or walk uphill.
Imagine a universe - infinite or not, as you wish to picture it - with a billion, billion, billion suns in it.
Imagine a blob of mud whirling madly around one of those suns.
Imagine yourself standing on that blob of mud, whirling with it, whirling through time and space to an unknown destination.