I shouted "HI, _____!!" out of the window.
He waved frantically back with a huge smile on his face. As I continued to drive off, he shouted "I GOT AN A ON MY SCIENCE TEST!!"
I, of course, shouted a response back. But no response could have expressed how proud of him I was. For the A. For making strides this year after a rough one last year (he lost his grandmother, and they were close). And for screaming it at the top of his lungs among his peers - which - at his age- sometimes takes more bravery than we know.