[tialaramex]

To me whether something is weird is distinct from it being usual or familiar.

It's weird that Americans tend to cheerfully eat cow meat but not horse meat for example. Much of natural language grammar such as the adjective order rules in English - pretty weird ("My old blue hat" is OK but "My blue old hat" is wrong!). The fact that there are five Fermat primes but then no other Fermat numbers seem to be prime is weird.