Why do foreigners taboo the number 13 and say it is unlucky?

Margaret Thatcher and Castro are both foreigners, born in 13. Look at how many cows they have raised in their life. There are countless celebrities born on 13. The ignorance of the old society led to so many taboos. There will be no such ignorance in modern society. The vast majority of modern people hold a hehe attitude towards those ignorant remarks. Few uneducated fools are just monkeys.