A childhood belief about imaginary friends

I had an imaginary dog called Shep for as long as I could remember. One day, my parents asked what sort of dog it was, and when I realised they couldn't see it too, he just ran away...

I didn't realise until I was 12 that sex was enjoyable, or involved penetration.

I really thought my Dad was throwing up a ball into that paper bag, and it was making a "thunk" noise.

I didn't realise Dad knew who had taken the piece of cheese, when he'd said "Don't take any cheese!" and turned his back.
Well, I was 3.