Birth

A staggering 30% of most people can remember being born.

Accents

People who have regional accents can't mimic other regional accents.

Blood pressure

Removing blood from yourself can effectively lower your blood pressure. Obvious really!

Wet

If you put the hand of someone who is asleep in a bowl of water then they'll wet the bed.

Trying this on your young children is non-conclusive as they wet their beds anyway, but it can be just as much fun.

Spiders

The number of miles crawled accross your face when you are asleep by spiders is on average 0.75 per year!

Finger in drill

If you tighten your index finger in the chuck of a handheld drill and get someone else to hold the drill, after applying power to the drill eventually you'll do a somersault.

A Googolplex

...is a number and there aren't enough atoms in the universe to write down this number in full! Actually this might be true, so perhaps not a candidate fict.

One from my childhood...

If you chew chewing-gum for long enough, not only does it get its flavour back, but it changes colour too!

Dot-to-dots

If you joint the dots up in reverse order, you get a different picture.

If you only join the prime numbers up you always get a straight line, this is called Dot's law named after Dot, who discovered it.

If you join the dots in a random order then you get a random picture.