Picture an apple in your head. No, I'm not insane. Just an apple.
Now picture two apples. Can you picture three? Four? Four apples, almost
instantly, are appearing in your head? Not two apples and then two apples.
That's cheating. Five apples? Six? Seven? Sorry, but you didn't picture seven
apples in your head. It's only possible if you're a genius. If you think that
you're one of those geniuses, try again. Did you really picture seven apples in
your head instantly and all at once?