When you realize that your already half way done with high school and you haven't done things you thought you would have done by then, or realize that the good times you have had won't last long.
This usually happens sometime during the summer after sophomore year. It can be triggered by things such as seeing some of your older friends graduating and leaving for collage, or when you see that you only have 2 more years in high school left.
It can cause things such as finally getting into shape (or at least trying to), talking to someone of the opposite sex that you used to be shy around, experimenting with drugs or alcohol, having sex for the first time and/or dropping everything to go hang out with friends knowing that they wont be there forever.
- When johnny saw his friend greg graduate, he went though his mid high school crisis and started to spend more time with his friends
- Jessica got drunk and put out when she realized that she was halfway through high school and never had sex before
Where you drive around late at night in neighborhoods armed with someone in the back seat and multiple empty (or soon to be empty) yoo hoo bottles. The person in the back seat rolls down the window and shouts "YOO HOO" very loudly and throws the bottle out of the window with great force thus breaking it. The driver then guns the gas and gets outta there and on to another neighborhood before the cops are called.
Person 1- "Hey dude you wanna go yoo hooing?"
Person 2- "no thanks, I got a citation for that last weekend."