Sixty turned so sexy this year.
For women, in particular, the ages from 60 to 80 are no longer a time to become invisible and move to the sidelines. This golden age has become the time to take center stage.
In 2013, women redefined which era of life can be our most powerful and most fulfilling. The same year that Miley Cyrus twerked her way into adulthood, Diana Nyad swam from Cuba to Florida.
Cyrus, now 21, could be a poster child for the long, harrowing "adultolesence" through which so many 20- and 30-somethings struggle to define themselves and transition into a grown-up life.
But Nyad, at 64, became a poster child for capturing dreams long deferred. And she was hardly the only woman this year who showed us what it means to hit your peak when people assume that peak is long behind you.
Janet Yellen, at 67, is set to become one of the world's most powerful people when the U.S. Senate approves her to chair the Federal Reserve System, the country's central bank and an influencer of the global economy. That sort of power and authority were long associated with men of a certain age, but all that's about to change.
Hillary Clinton could win the White House at 69, a year younger than when Ronald Reagan took over the presidency. In her four years as secretary of state, Clinton kept an indefatigable pace, traveling almost a million miles to 112 countries.
Senator Elizabeth Warren, 64, transformed from Harvard law professor to power broker leading the charge for change within the Democratic party.
And the gifted Alice Munro won the Nobel Prize in Literature this year as the "master of the contemporary short story" at the age of 82.
When a young athlete needs inspiration to power through a difficult challenge, let her imagine Nyad swimming for days in a face mask to protect her from poisonous jellyfish. When a frustrated young artist wonders if her work will ever be recognized, let her read the exquisite prose of Munro. When young activists despair of ever creating a better world, let them know that change and progress are not exclusive to any age.
There have always been role models rejecting the notion that vitality and worth are somehow tied to a number. Consider Meryl Streep, 64, widely considered one of the greatest actors of our time, and still a mere neophyte compared to 91-year-old Betty White. But in 2013, a critical mass of women drove home this point.
Given how much longer it takes to get a foothold in one's career in this economy, and how much longer people are waiting to get married and start having children, it makes sense that the height of accomplishment can now come long after what were once considered one's glory days.
We've shifted the entire life cycle by increasing our life expectancy, extending the period of fertility and launching from one career to the next. We expect to be working longer, so our full potential may well be realized sometime beyond 60. In a youth-obsessed culture, we are better served by turning our gaze forward, looking with anticipation at what may become our best time yet.
The best part of Nyad's story came after her feat of perseverance and strength.
In her 20s, she had denigrated and criticized the same swim in 1978 when it was completed for the first time ever by a 65-year-old Ohioan named Walter Poenisch. She called him a cheat for using fins and taking short boat breaks. Nyad would later face similar criticism from marathon swimmers for her own use of a protective face mask and bodysuit.
Nyad was quoted in the Miami Herald in 1978 before Poenisch's attempt: "A man who's 65 years old and very overweight is not going to swim for two days nonstop."
He proved her wrong. She recently said she regretted the words from the foolish days of her 20s.
Perhaps conquering summits in your 60s and beyond allows the added advantage of wisdom.