On May 8th you could wear a squid hat to maybe get some laughs or maybe get some strange looks but it's all just for fun.
Dude 1: *Wearing a squid hat*
Dude 2: Why are you wearing a squid hat?
Dude 1: Because of its National Wear A Squid Hat Day
Dude 2: Oh cool *puts a squid hat on* now we are both wearing squid hats