On October 18, Zac Efron turned the big 2-8. We celebrated this auspicious occasion by taking an investigatory look at every time one of the actor's muscles appeared to be staring straight in our direction . (And, it was glorious.)The b-day boy had his own message to share with the world this Sunday. The We Are Your Friends star posted a throwback pic on Instagram of himself and his cousin, Emily, on the beach when they were children.The post is bittersweet, with a poignant caption that reads: "Happy birthday to my cousin and best friend, Emily, who passed away from cancer 2 years ago," he wrote, adding, "She was 28 like me."