Age is nothing but a number — and 70 is the new 40, right?

My husband always expects me to find something to cry about on my birthday.

That’s been my history, particularly on the “9s.”

After rushing to be a grownup, I spent my entire year as a 29-year-old lamenting turning 30.

Thirty-nine was the year I realized that, for all intents and purposes, half my life was over.

A tearful 49th birthday paved the way for a 50th birthday party — my first in 27 years.

I had a good reason to cry on my 59th, as I was finishing with chemo for breast cancer.

After that, I started running away. I’d pick my birthday to travel or cruise — as if putting distance between me and home would somehow soften the blow.

But, amazingly, this year there were no tears on my 69th birthday.

Not even the choking kind that can catch you off-guard.

It’s as if 70 has really become the new 40.

No, it isn’t the promise of Botox injections that’s making me feel so hopeful. Frankly, I can’t understand how anyone could sit through that many sticks.

Nor is it the miracle of makeup, although I’ve got to give a skilled makeup artist all the credit for my new column photo.

But makeup artists aren’t magicians. Some signs of aging, like hearing loss, you just can’t hide.

So why bother?

The other day, I saw the most striking elderly woman. She was cheerful, trim and had a head-turning mane of white hair.

Beautiful.

To some degree, unlike the stigma of racism and sexism, ageism is acceptable in our society.

Maybe we don’t mean to, but we judge older females so harshly that many of us hide our real age.

I have a girlfriend who has to be my age or older. But whenever we celebrate her birthday, she absolutely refuses to say how old she is.

“A woman who tells her age will tell anything,” she once told me, smacking back my inquiry.

I suppose that, when she passes, we’ll all be shocked.

In recent years, I’ve spent my birthday with twin sister Marie. This year, she stayed in Texas doing nothing, and I stayed in Chicago.

Still, we had the same vibe.

“I did something different this year! Absolutely nothing. Saving it for the big 70…2019!!,” she texted.

My father died suddenly on my 57th birthday — two months before he would have turned 81. My mother will be 91 in August.

So the odds of longevity should be in my favor.

But as Sadie Delany, half of the famous African-American centenarians immortalized in the memoir “Having Our Say,” put it:

“Life is short. It’s up to you to make it sweet.”

For all of you about-to-turn-70-boomers, it’s still not to late to make lemonade out of lemons.

After all, the Delany sisters found fame at 100 years old when journalist Amy Hill Hearth interviewed them for an article in The New York Times, published in 1991, that led to a memoir. The book stayed on The New York Times’ hardcover best-seller list for 28 weeks and the paperback list for 77 weeks.

Sadie Delany died in 1999 at 109. Younger sister Bessie Delany died in 1995 at 104.

There’s a stage adaption of “Having Our Say,” directed by Chuck Smith, Goodman’s longtime resident director, now running through June 10.

If you think that listening to two actors on stage portraying centenarians would be boring, you’re wrong.

Framed around the sisters preparing their annual birthday meal for their departed father, the rapid-fire conversation will put you in a time machine and keep you engrossed.

If you haven’t seen this play, catch it before it ends.

The nuggets of wisdom (and truth), not to mention the awesome performances by Ella Joyce as Bessie and Marie Thomas, portraying Sadie, will make you see aging for the awesome gift it really is.

My birthday wish this year? It was simple:

Lord, help me make peace with the past, be grateful for the present and hopeful for the future.

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‘ZEBRA SISTERS’ PODCAST: Why black-white home ownership gap persists

Courtney Jones, president of Chicago’s Dearborn Realtist Board, joins the conversation on Episode No. 17 of the “Zebra Sisters” podcast cohosted by Mary Mitchell and Leslie Baldacci. Every week, they explore race relations from the viewpoints of two women, one black and one white. New episodes every Saturday. Subscribe (free) on iTunes and Google Play Music — or listen to individual episodes on the Sun-Times’ website. Email zebrasisters@suntimes.com or give them a shout-out on the Zebra Hotline at (312) 321-3000, ext. ZBRA (9272).