We all have our phobias. And we are pulling with more or less stealth when some absurdity comes up with the idea of opening an umbrella in a closed place. When they pass us the salt shaker in hand, or worse, they spill it, cross the cutlery or break the bread upside down. Nor do we remain calm when passing under a ladder (beware of scaffolding and moving cranes, there is always one hidden there) or, if it breaks, horror!, a damn mirror. The list is personalized by everyone in their own way and includes worse moments, like when you run into that grim neighbor who insists on wearing yellow shirts.
Collaphobia is the clinical name for the aversion to Friday the 13th, a complication of triskaidekaphobia or that Western terror of the 13th. But here, and in general throughout the Latin world, we are more likely to get sick when the 13th wears a Tuesday ( one arrives in September and we finish off with another in December), while in Italy the sambenito is for the 17th. And more, again, if it falls on a Friday as it will in June. Reasons? They have them.
In ancient Rome, 17 corresponded to the anagram that suggested I have lived and, therefore, I am dead. The Pythagoreans did not like it either because "the 17 stand between 16 and 18 like an obstacle that breaks the ratio of one and one eighth at unequal intervals." Sounds good. There are superstitions for everyone. Than? Do we also become haters of 17?