I’m old enough to know the problems an 80-year-old man can face. I get why Democrats worry.

The gait stiffens, hearing gets iffy and words – names! – can be elusive.

But old people know a lot that young people don’t. We know, first of all, what it’s like to be young. Young people don’t know what it’s like to be old.

Joe Biden remembers being an impatient, maverick 29-year-old who took on an incumbent Senator – and beat him.

He remembers being Joey from Scranton. That’s where he learned the blue-collar liberalism he stands for now.

After 50 years in politics, he knows a lot about the country, its people and how Washington works, or doesn’t work. That’s how he passed the most consequential economic and social legislation in decades.

He knows family, loss, grief and love.

What a contrast to the Trump family’s constant grasping and money-grabbing.

When you’re old, you can do a lot if you take care of yourself. Biden’s recent physical reported he is six feet tall and weighs 178.

A lot of guys, a lot younger, envy that.

(Pardon the presumption, Mr. President, but some advice: Try yoga. Or tai chi.)

Biden cut a slim, strong figure striding through Kyiv with President Zelensky, after a transatlantic flight and 10-hour train ride.

Compare that to a lumbering Trump heaving himself out of a golf cart.

Americans have a history of electing fatherly, even grandfatherly, presidents, even with health problems: FDR, Eisenhower, Reagan.

So, Joe is OK.

Besides, 80 is the new 60.