Apparently public hangings regularly took place on Fridays with 13 steps to the gallows. At a beheading the guillotine blade falls 13 feet and the tarot card number 13 is the Death Card which explains a lot of our fears associated with the number. Hotels don't take risks and generally don't have a room number 13 and often don't have a floor 13 either.
July has another Friday the 13th coming up in 2012 so good luck with that. You could consider moving to Italy where Friday the 17th is unlucky and 13 is a lucky number but many worry about both dates so maybe not your best move.
As well as days and numbers we have superstitions along many other themes. I've known sports fans to panic about wearing their "lucky underpants" on match days or about completing a ritual before a game, in an OCD fashion.
Seven years bad luck for breaking a mirror probably relates to the time when mirrors were considered to be tools of the gods to see into our souls so a broken mirror meant your soul was separated from you. To counteract the spell you need to wait seven hours (one for each year of bad luck) before picking up the broken pieces, and burying them outside in the moonlight.
The dinner table has plenty more superstitions to keep us nervous. If you spill salt you can save yourself from bad luck by throwing a pinch of salt over your left shoulder which is towards the devil. I'm not sure who's on your other shoulder and what they think about salt.
When you finish eating a boiled egg, remember to push your spoon through the bottom of the empty shell to let the devil out – he really does get everywhere, it seems.
Maybe it was an itchy palm that caused the cutlery to fall. If it's your right palm that itches then you're going to receive money but don’t scratch it as that stops the money from coming. If it’s your left palm that is itchy it's OK to scratch as that means that you'll soon be paying out money.
The good news is all you have to do to break a bad luck spell is turn around seven times clockwise. Lordy knows what would happen if you turned the wrong way so let's not try it.
Superstitions, myths, folklore and old wive's tales can be blamed for many of the bizarre habits we follow and I wonder how many have just been made up over the years to try and account for our strange behaviour at times. We may laugh at many of these superstitions but I'm sure we've all crossed our fingers for good luck so we're probably more influenced than we like to believe.