On this fine Throwback Thursday, Amanda Seyfried is bringing us all the way back to 2003, when she filmed her very first movie. You might have heard of it; it's called Mean Girls, and it's loaded with sage fashion advice, quite a few bad b*tch moments, and, of course, the lovably ditzy Karen Smith. In her nostalgic snap, Seyfried calls back to not one but two of her character's most iconic quotes. The picture, of course, depicts her burgeoning career as a weather woman — where she puts her "ESPN" (and weather-sensitive breasts) to good use. The best part, though, is her expert use of a hashtag: "#imamouseduh." The line goes down as one of the most quotable moments of the film, surely uttered hundreds of thousands of times by countless Halloween mouses in the years since the release. Let's all just bask in the glory of this moment.