"The Trending 20" is a regular series where we round up interesting, informative and hilarious tweets from worldwide Twitter trending topics, fueled by young tweeters on the interwebs. Have one to submit? Give us a shout @huffpostteen.
Of all the things you learn in high school -- from facts about the Civil War to complex algebra equations -- chances are, it's the ones you learn outside the classroom that will stick with you for the rest of your life. According to the Twitterverse, realizations about friendship, fitting in and self-acceptance are among the most important things they learned in the years between middle school and college. This morning, current and former high school students took to Twitter with their high school life lessons, propelling the hashtag #HighSchoolMadeMeRealize to trend worldwide. Check out our 20 favorites in the slideshow below and share your own realizations in the comments!