Dear Mr President:Allow me to welcome you into the ranks of America's octogenarians, which you will officially join Sunday. I'm tempted to describe our group as a small but plucky bunch, but that would be wrong: With octogenarians in this country numbering more than 12 million and counting, according to census data, we constitute an army.

What we might rally to fight is hard to tell, having already lost the battle against old age.

That said, "old geezer" stereotyping awaits you, but don't let it get you down. Millions of us, you will find, aren't living out our lives in retirement villages dotting the Sun Belt. Or in nursing homes dutifully waiting for the Good Lord to call us home.

For sure, Mr President, there are those among us who have more than their share of disease and infirmity. But look around and you will see huge numbers of women and men in their 80s who are out and about, leading independent, active lives. And many of us are also enjoying more satisfaction than what life yielded during our 30s, 40s and 50s. Perhaps it's because we are long past the days of worrying about climbing the next rung on the ladder.

Octogenarians, pure and simple, aren't looking for something bigger and better. I suspect this is pretty much where you also find yourself after nearly two years into your presidency. You are at the top of your pay scale.

The chief difference between you and most of us is that you still have a full-time job. Which I'll return to a little later.

Of this, one thing is assured: Regardless of past life experiences, you will gain a different perspective on the surrounding world once you cross the age-80 threshold.

I know that with three years of octogenarian life under my belt, it's all I can do to navigate our nation's capital with a straight face. The suffering that younger generations of manoeuvring politicians, camera-ready pundits and president wannabes put themselves through to make names for themselves is laughable - falling-down funny, in fact, were it not for the sad toll that it takes on their lives.

I'm sure in your career you have watched bunches of power players strut and fret upon Washington's stage. But there's nothing like seeing it from the vantage point of an age when you are beyond it all.

Alert: Some up-and-coming generations like to take out their misery on older people, attributing an occasional stumbled or forgotten word to (tut-tut) advancing mental or physical impairment.

Don't be surprised, even though you are president, if visitors, and even some staff, start to treat lightly what you have to say. They might even try to leave you out of meetings, for goodness' sake.

Ageism also seeps into public service, sports, entertainment and, yes, the world of journalism. Ageism, Mr. President, comes with the territory.

An unsolicited piece of advice: Act your age.

Don't resort to behaviour aimed at convincing the public you are younger than you are. Logrolling, dead-lifting or climbing the stairs of the Washington Monument wearing a heavy backpack aren't exactly things to take up at 80. Do all the stuff your doctors and family tell you to do. Watch your diet, exercise as much as you can, get enough sleep (naps are my favourite). But, Mr. President, ageing is beyond your control. Do it with grace.

Which gets us to what to do with the rest of your life.

Think back to the America you inherited on January 20, 2021. You looked out on a country stricken by a once-in-a-century virus. You spoke to an America that had lost jobs by the millions and where businesses posted "closed" signs by the thousands. You stood on grounds defiled by a riotous mob, stoked by a defeated president who tried to crush a foundation stone of US democracy - the peaceful transfer of power.

You promised to get on with the business of governing: fighting the coronavirus, dealing with painful economic and social realities, addressing the moral and fiscal imperatives of the climate crisis, stepping up against the attack on our democracy, restoring America's role in the world.

Look around, Mr President. You done good.

Sure, there's much more left. It is always thus in the world's strongest nation with its globe-leading economy and dynamic, multicultural population.

Some of us would love to have you in both places: in the Oval Office and on the back porch telling stories while occasionally doling out elder-statesman advice to the rising generation of leaders behind you.

We can't have it both ways, Mr President. Neither can you.

We'll leave a door open, just in case.