The 13th number is bad luck. In Christianity 13th is bad because it is said to be the disciple, Judas. Loki is also said to be the 13th Norse god (sorry Marvel fans) and the code of Hammurabi omitted a 13th code. You can practically see everything revolves around omitting 13, clocks are up to 12, months are up to 12, teenage years start at the age of thirteen (angsty, spoiled evil stages of your life) and many more.

Triskaidekaphobia is a severe fear of the number 13 so that may also be a reason why there are no 13 in other everyday objects. Another number is also feared upon but it is more known in Asian countries and that is the number 4. Just know that 13 and 4 might be bad but together they can form 143 and I think that is far worse.