It's my birthday this week.I don't have a problem telling you my age - 56 - because I'm younger than many and older than some.I think about this a lot - for my grandmothers, fifty-six was a completely different experience.Because their life expectancy at birth - with no antibiotics, anesthesia or other modern medical advances - was somewhere around forty-five or forty-six. Living beyond that must have seemed like bonus time.For my grandmother Bea, who died at age 67, turning the age I am now meant that she only had twelve more years of living ahead of her.Of course, she didn't know that.As a young child, all I knew was that Mama Bea looked old, and even pictures of her at fifty-six don't look the way I look at fifty-six.My other grandmother, Fern, lived to 101 1/2. Turning fifty-six was well beyond what she had expected, but she had an whole other entire lifetime ahead of her.Of course, she didn't know that, either.I don't imagine either of them would have been able to fathom my life at fifty-six.Having a business - well, Bea owned and managed rental properties so she could have understood that pretty clearly - but working out of a home office, coaching men and women in Europe, Asia, Latin America as easy as talking with someone in Tulsa or Topeka? Unfathomable.Making a very good living at it, too? They'd accuse me of making up tales.Being at the height of my professional power and connectedness? Now, there they would be utterly dumbfounded.And maybe just a little bit proud.Because in their day, it was men who were at the pinnacle of their professional careers - and earning power - at fifty-six.And now I am, too.This is a huge shift that has occurred in my lifetime. Once upon a time, a fifty-six year old woman would be considered old, ready for the pasture, useless.Today, though...Today, this particular fifty-six year old woman is just getting started.My work has never been better. My reach is global. My impact is lasting. I am creatively on fire.And, most importantly of all...I'm having one hell of a good time.