Learnt a new word recently: triskaidekaphobia. The word is broken down into 4 greek words “tris kai deka phobia”: three and ten fear.
What it means is the fear of number 13.
Each year has at least one Friday the 13th. However, the years 2009, 2012 and 2015 should have three Friday the 13th in them.
You can show off this new knowledge by saying to your friend, “You don't suffer from triskaidekaphobia, do you?”, and listen to your friend goes “Huh?”