Technically speaking, everybody has been aging since the day they were born. However, it usually takes a little while for the mortality of it all to catch up with us. Many of us are lucky enough to spring into adulthood with flexible joints, minimal hangovers, and fast metabolisms, then one day it just seems to unceremoniously change.
It's true, getting old is not for the weak. Let's be honest, though, it really could be a lot worse. Not only that, most of us probably have a lot more life to go. Our thirties might be the first time many notice that things aren't what they were, but it's still supposed to be the prime of our lives. That's the point that @faganchelsea has been making after getting fed up with the stereotype that being in your thirties automatically makes you old.
Numerous viewers chimed in to agree that the big 3-0 isn't an automatic sentence to a retirement home. Let's be honest, the majority of us are overjoyed to not be 16 any more.