Do you remember the ins and outs of AP Biology still? How about AP World History?

Now, while you might not want to be reminded about high school- having a strong foundation in some core courses, like biology and history, can be immensely helpful in your life: from future classes you’ll take in college to dinner conversation you’ll have with your friends.

This weekend, head over to Crash Course, a YouTube channel where two brothers (from the famous Vlogbrother channel) take turns covering the fundimentals of both of these subjects. From episodes about ATP to Alexander the Great, they break things down and make it easy to catch back up on a few topics you might have missed in high school.

It’ll be worth spending an hour to catch up to where they are now, and then subscribe to their channel for their future, weekly updates.