Did you ever do that thing as a kid where you press your eyes real hard when they’re closed with your thumbs of the heel of your hand until you see all kinds of crazy colours and patterns?

The longer you pressed, the more the colours would flare. You’d see fractals and waves, and bursts of white hot light. You’d make out shapes of things, paths and curves.

Then when you stopped pressing your vision would come back slowly, going through all kinds of shades from neon to dark.

I’m 43 and I still do it sometimes.