A sizzling 76, former Vice President/U.S. Senator/Serial Hugger Joe Biden will make his third run for the White House. His age is an issue for some people. But why?

He's a year younger than 77-year-old Bernie Sanders, who seems to get a pass because we are used to him as a presidential contender. President Donald Trump is 72; the titular leader of the Democratic Party, Nancy Pelosi, is 79.

Isn't it weird that even though Millennials (ages 23-38) have surpassed Baby Boomers (55-73) as America's largest cohort, or age group, the leaders of the presidential sweepstakes are well beyond what's thought of as retirement age, which is itself a shaky concept?

The Gray Panthers was founded in 1970 by Philadelphian Maggie Kuhn, when she was forced to retire from a job she loved because she hit the magic age of 65. She lost her job, but launched a movement.

A tireless quote machine, Maggie said there were six myths about old age: "That it's a disease, a disaster. That we are mindless. That we are sexless. That we are useless. That we are powerless. That we are all alike."

Predictably (because they are my age peers), I say the gray-haired guys (not to mention the orange-haired one) still are buzzy. They are a finished product.

"Aging is an extraordinary process where you become the person you always should have been," said my peer David Bowie, who died at 69.

The process also rewards you, he did not say, with an annoying number of aches and pains.

For half my life, the Big Thinkers have described America as a youth culture that worships the young, new and unwrinkled. I found that cool when they were talking about me, less so now that I've aged out.

Does the appeal of septuagenarian candidates mean America has swapped youth culture for ancestor worship?

I doubt it. Sanders, Biden and Trump benefit from name recognition.

When I engage with online critics, the point of attack is my senior status, more than my race, religion, gender or political views. Almost without exception, this comes from the Left. The same people who hyperventilate over racism, homophobia, misogyny, Islamophobia, transphobia, and xenophobia, are comfortable whipping out the club of ageism.

Does it bother me? Not really. Age brings a sort of serenity. They often think I don't get it, whatever "it" is to them. I do know that I have been 25, and can remember what that feels like, but they are clueless about how and what you feel at 50.

While our mind may be fuzzy on some details, we have the maturity to understand how and why things work. There aren't many surprises.

But there are some — like health, which can go south quickly, even for those with apparent vigor.

That's why I'm certain that should either Biden or Sanders be the Democratic nominee, the vice presidential candidate will be at least one generation younger. And it won't be a straight, white male.

Stu Bykofsky has been a columnist with the Philadelphia Daily News since 1987.