Friday the 13th - Share experiences

I am not a superstitious person, but I do wonder about the origins of ‘traditions’ such as the supposedly unlucky Friday 13th….

Why is this doomed to be an unlucky day? In some cultures the number 13 is supposed to be lucky….
As we are all masters of defining and creating our own luck, is this just a paranoia, that once we ‘learn’ of its bad luck we programme our subconscious to believe it will be unlucky and therefore manifest bad luck for ourselves??

Please share your Friday 13th experiences both good and bad (either from the past or whats going on for you today) and any historical knowledge surrounding the reasons for this superstition.

I believe it is a paranoia.
The number 13 in my culture is not doomed or better said I do not know if it is valued as good or bad at all.
We have a celebration though on the 13th day of the year It normally falls on April 2nd, we have to be outdoors on that day. So traditionally on that day we do pic-nics and have gatherings outdoors playing etc.
Actually for me the number 13 is good number. Especially ever since I am aware of the power of the thoughts, I like every number :-)