She was not my grandma. We both knew that. My grandparents had been wonderful. They died years ago.

This grandma I met only recently. Met her in a nursing home. Visited her in hospitals. She was 79 and I never saw her healthy.

Come to think of it, I never saw her standing up. I saw her on gurneys. In beds.

Once I saw her sitting in a wheelchair, doing rehab with a therapist she had to pull little plastic tabs out of a wad of goopy clay, and she rolled her eyes as if to say, “Can you believe this? A woman my age? Playing with goop?”

That was about as active as I saw her. Unless you count smiling. Or scrunching her face. Or blowing kisses.

Or talking. Whoo, boy. If talk were competitive, she could have won medals. She spoke succinctly, but her words pricked the skin.

“You look good,” you would say.

“You’re a liar,” she’d shoot back.

“You haven’t eaten anything,” you would say.

“Well, now, honey,” she’d answer, nodding at a piece of hospital meat, “who on Earth would eat that?”

She saved her best comebacks for the important stuff. Like when her granddaughter would say, “I love you.”

“I love you most,” she’d answer.

Not “I love you more.” “I love you most.” She smiled when she said that, as if to say, “I win.”

She was not my grandma. She belonged to a friend and co-worker who had been visiting her for months, ever since old age had knocked this once-strong woman to her knees.

My friend would leave work quickly on the days she was visiting. One day I offered to accompany her. She said OK.

Her grandma’s name was unusual Clista Gillis a bouncy, Western name befitting a woman who had lived in the Oklahoma plains and the Nevada desert. She was, by the time I entered her life, a frail, thin, sharply boned person, barely the size of a 12-year-old girl, but with sparkling eyes, white hair and a grin somewhere between an angel and a saloon keeper.

On that first visit, she sized me up, then lifted her hands in a “come hug me” gesture. And that was the end of any distance between us.

“Do you have your grandmothers?” she asked.

“Mine are all gone.”

“Well, then, sweetheart, I’ll be your grandmother and you can be my grandson.”

“That’s a deal.”

“My handsome grandson,” she added, acting like a grandmother already.

I can’t give you her thorough biography. I knew she was part-Native American, she had five children and adopted a teen-age girl, she had lived in Las Vegas, once worked as a waitress and loved rock ‘n’ roll music.

“You know,” she said, not too long ago, “Van Halen just isn’t as good since David Lee Roth left.”

Who wouldn’t fall for that?

She was not my grandma. But she treated me like a grandson, with unconditional love. And every time a report came of her failing health, I felt that familiar skip of the heart.

She had several scares. Couldn’t breathe. Went unconscious. Once or twice, they thought she was gone, but an hour later, she was awake. One time, when she came back to life, she said she had been having the sweetest dream about a beautiful meadow.

“So green,” she whispered.

When asked if she wanted to leave that meadow, she shook her head.

You knew it was a matter of days.

During her last visit, my friend flipped on her grandma’s favorite TV show. It was halfway over.

“I’m sorry, Grandma, I thought it started later,” she said. “I was wrong.”

Her grandma shook her head.

“You were never wrong,” she said.

That was not a throwaway sentence. What she meant was simple. Grandchildren are never wrong in the eyes of their grandparents. And because of that, grandparents are never wrong in the eyes of their grandchildren. Their natural ones and the ones they pick up along the way.

“I love you,” you would say.

“I love you most,” she would answer.

That’s a grandmother’s trump card. Clista lay it down with grace, then left this Earth for a greener meadow.

She was not my grandma. But I miss her already.

Mitch Albom is author of the best-selling book, “Tuesdays With Morrie.”