Meryl Streep's birthday is on Monday, and in honor of the megastar turning 66, we thought we'd take a look back — way back — to her high school days of prom and pompoms! Meryl grew up in New Jersey and attended Bernards High School in the late '60s. She clearly took school seriously, as she went on to get her B.A. in drama from Vassar College, studied as an exchange student at Dartmouth, and earned her M.F.A. from Yale School of Drama. But it wasn't all work and no play for teen Meryl. As you'll see in these pictures, she was also busy showing her school spirit as a cheerleader. Let's flip through the yearbook pages to get a look at birthday girl Meryl Streep's pre-Hollywood high school days, then see more of the best celebrity yearbook photos!