Eva Amurri posted adorable shots and outtakes, Rachel Bilson admitted leaving coffee in the pantry, Dominique Dawes joked about blank "first day" signs, and Rob Mariano confessed not driving his daughters to school. Jessie James Decker shared her three eldest in uniform, and Mia Talerico reflected on her own "last first day" as a senior. Across the board, celebrities mixed pride, humor and nostalgia as a new school year began.