Patrick Dempsey made a splash when he debuted on “Grey’s Anatomy” as Dr. Derek Shepherd, famously nicknamed “McDreamy.” Most viewers assume the name comes purely from Dempsey’s good looks, but “McDreamy” actually has a real origin story, as told by “Grey’s” creator Shonda Rhimes.

Rhimes told Oprah Winfrey, “When we were shooting the pilot, Patrick was seriously the most adorable man we'd ever seen [...] We'd watch the monitor and think, 'Look at his dreamy eyes!' So we started calling him Patrick McDreamy, and it stuck.” In other words, it’s all about his eyes.

As for how Dempsey feels about being McDreamy, he admitted that “It's going to be there for the rest of my life so I have to accept that as a fact,” but he has no hard feelings about it. Dempsey also revealed a childhood nickname that’s very different from the one he has today.

Dempsey told “Nightline,” “I was really a small guy growing up and so I was 'the amoeba.' That was my nickname [...] I was a late-bloomer.” For a “late bloomer,” Dempsey certainly hit the jackpot later in life, becoming a teen heartthrob in the ‘80s and ‘90s before making it big on “Grey’s.”