Michelle Trachtenberg couldn't wait for Throwback Thursday to post a cute tribute to Harriet the Spy. The classic '90s movie turned 20 this past Sunday, and Trachtenberg wanted everyone to know she still feels affection for her first film role.The actress posted a black-and-white still from the movie on Instagram writing, "Twenty years ago today, July 10th 1996, Harriet The Spy opened in theaters. I was 10 years old, this was my first movie, and my dream come true. I will always be honored to have been the girl who brought #harriet to life." She also included a classic quote from film, "I want to see the whole world, and I want to write down everything!"Trachtenberg has been on a throwback streak as of late. Last week she posted a photo from her early days on Buffy the Vampire Slayer (with co-star James Marsters). Maybe she'll post something from Gossip Girl next?