Reflections...

Triskaidekaphobia
The fear of the number 13 is called triskaidekaphobia. The number 13 has been considered unlucky for a long time. Early Romans thought 13 was a sign of death and destruction. The number 13 and a Friday are sometimes considered very bad luck. Lucky for us there are a maximum of three Friday the 13th in one year.
Fascinating Facts about Friday the 13th
Greek philosophers called 13 an 'imperfect' number.
Friday was the common day for people to be hanged in the past.
Hangmen were once paid thirteen penny.
Many hotels have no room number 13
Many buildings do not have a 13th floor.
Many airplanes do not have a 13th row.
Many ships will not start a voyage on the 13th, particularly, Friday the 13th.