They should make learning how to change a tire and jump start a car required component of high school education.
The near certain doom of your bank account when you realize that you only brought a card instead of cash to Barnes & Noble.
#1. When you come back from studying abroad and almost or actually do use Spanish for reflex interactions such as greetings and ordering food and then the other person just kind of stares at you and you stare back for too long for it to be normal. Eventually you realize you used the wrong language and have to try and recover without allowing them to believe that you are actually crazy.