Happy 73rd birthday to the one and only, Mark Harmon! It's hard to believe that our favorite silver fox has reached this milestone, but let's be honest, he just keeps getting better with age. From playing Gibbs on NCIS to charming us all in Summer School, you have captured our hearts and inspired us for decades. Here's to another year of living life to the fullest and making us all swoon. Have a fabulous day of celebration, you handsome devil!