I can only speculate that it's a critical mass of life experience that causes the shift. I cannot say why it occurs so reliably at 30 (not 29, not 31) for anyone who's paying even a little bit of attention. It seems like 30/29 ought to be no different than 29/28 or 31/30, but it's not. I still didn't believe it at 29, no matter how many people told me so, and thenÂ…I turned 30! It doesn't mean you magically have all the answers or anything like that, sorry to say, but it gets a lot easier to discern what matters from what doesn't, and a lot easier to figure out how best to deal with whatever life might happen to throw at you. Which is good, because it arrives just in time; the world will tolerate a great deal of behaviour from a twentysomething that it simply won't have from a thirtysomething.
