Here Is Proof That Birthday Girl Courteney Cox Hasn't Aged Since High School

Courteney Cox has been gracing our television screens way before she played the obsessive compulsive but loveable Monica Gellar on Friends (remember she was Alex P. Keaton's steady grad school girlfriend on Family Ties?). That's partly what makes it so hard to believe that she turns 51 today. We need her beauty secrets stat!

Surely, it also helps that Cox recently got engaged to a hot younger man named Johnny McDaid (following in the footsteps of her character on Cougar Town?), or maybe it's her cute new lob haircut. As for when she feels most beautiful she toldInStyle last year: "Weirdly enough, I probably look the best in the morning. I'm a little plump and it’s the time before I get dehydrated throughout the day and forget to drink water. But if I've slept well, I probably feel the best first thing in the morning. I love sleep. But honestly, I really feel the most beautiful when I'm happy, like now. I'm in a really good place right now."

Sleep and water. If that will help us look more like Cox, we're all for it. Toast to the birthday girl with a look at her beauty evolution through the years.

PHOTOS: Here's Proof That Courteney Cox Hasn't Changed Since High School