There’s another candle on your birthday cake.

Whatever.

Your back hurts, your knees hurt, and it was hard getting up this morning, then you lost your glasses and spent 10 minutes looking for them. One stupid candle won’t make you feel enlightened but in “This Chair Rocks” by Ashton Applewhite, you’ll see how to grow older without aging.

Ashton Applewhite hates the way we talk about people over 50. Specifically, she hates “the elderly” and “seniors,” as well as “elders” because those terms have generally bad connotations. Instead, she suggests we change our language to “olders,” because the word “emphasizes that age is a continuum.”

Aging, you see, is what she knows — not just because she’s sixty-something, but because she writes about the subject. She knows there are lots of myths about aging, and that the truth is better than we think.

A mere 3 percent of Americans over age 65 live in nursing homes, for one, and most of them “can think just fine,” which means they don’t have any problems with dementia. Most olders, in fact, remain active, independent, and enjoy fashion, dating, sex and travel. To think differently is indulging in ageism.

Once you know how to spot ageism, Applewhite says, you can combat it.

Forgetting that olders are still consumers is ageism. Howling that near-retirement-age employees take jobs from younger workers is ridiculous — and ageism. Getting shamed for needing a wheelchair is ageism. Being scolded for wearing something you love but that someone has decided is “too young for you”… ageism. Absolutely.

Furthermore, says Applewhite, your brain is probably fine; cognition declines to a certain extent in older years, but aging enhances thought processes and besides, younger people forget things, too. You can keep your brain sharp by working your body.

Remember that “aging is not a disease,” and you shouldn’t be ashamed of it because “Sixty isn’t the new forty, but it is a new sixty.”

Oh, and those aches…? You shovel, you garden, you walk, you dance. Maybe the aches came from living.

Your next birthday is arriving soon, and you’re not sure whether to dread it, admit to it, or lie about it. You’re not sure what to think, but after reading “This Chair Rocks,” you’ll know exactly.

Author Ashton Applewhite is, as you can imagine, a proponent of embracing your years, an action that she shows is beneficial in many ways for both quality of life and longevity. Those are happy words for the person who seizes their existence and wrings every ounce from it. They’re a shoutout to anyone who uses a hearing aid or wheelchair without embarrassment, and a comfort to those who struggle to ignore the “shouldas” that other people fling. They’re advising words of the MYOB sort: enjoy your years because whose business is it what you do?

That’s counsel that could turn your thinking around, or it could make a great 50th birthday gift to someone with dread on their mind. “This Chair Rocks” proves that getting older is icing on the cake.

• By TERRI SCHLICHENMEYER, Bookworm Sez