So, are shishito peppers spicy? No, most of the time. But sometimes, yes, sometimes they absolutely are. They are the shy friend who suddenly tells a killer joke out of nowhere.
My advice? Cook them, eat them, and embrace the chaos. That one spicy pepper won't ruin your meal; it'll make it memorable. And hey, if you get the spicy one, you just won the shishito lottery. Congratulations… and I'm sorry.
Now go forth and gamble with your taste buds. You'll probably win more than you lose.