Mama seemed to have all but given up on this world.

At 59, the chimpanzee was suffering a long, achingly slow illness, at the Royal Burgers Zoo in the Netherlands.

Closeup of chimpanzee's face Mama had been a long-familiar face at the Royal Burgers Zoo in the Netherlands. (Photo: Snapshot from YouTube video/Jan A R A M van Hooff)

She wasn’t so much raging against the dying of the light so much as embracing it. It was April 2016 and the chimp, long an icon at the zoo, was nudging away every spoonful of food offered to her. Instead, she curled up into a ball, seemingly her own source of comfort at the end of a long and storied life.

Sick chimpanzee lays in straw The terminally ill chimp turned aside every effort to comfort her. (Photo: Snapshot from YouTube video/Jan A R A M van Hooff)

That is, until another kind of light appeared. Jan van Hooff paid her a bedside visit. The Dutch biologist met Mama back in 1972 and, over the decades, they had formed a potent bond.

A video the professor posted on YouTube shows Mama taking a moment to recognize her old friend. And then comes a screech of joy.

Man reaches out to touch chimpanzee It took a moment for Mama to recall her old friend. (Photo: Snapshot from YouTube video/Jan A R A M van Hooff)

Chimpanzee looking up at man She looked up warily. (Photo: Snapshot from YouTube video/Jan A R A M van Hooff)

Chimpanzee reaches out to man And then she remembered. (Photo: Snapshot from YouTube video/Jan A R A M van Hooff)

The patient, who had shrugged off every entreaty from her caregivers, outstretches her arms. She grins and howls and presses the man tightly against her.

Chimpanzee hugs man The old friends had an emotional reunion. (Photo: Snapshot from YouTube video/Jan A R A M van Hooff)

“Her reaction was extremely emotional and heart-breaking,” van Hooff notes in the introduction to the video.

Of course, animals — from whales and dolphins to apes to octopuses — have long shown that they make emotional connections as at least as powerfully as humans do.

But there was something else in this reunion: a kind of reminiscing between two friends who hadn’t seen each in a long time.

Chimpanzee hugs man Mama wrapped her arms around the biologist and held him tightly. (Photo: Snapshot from YouTube video/Jan A R A M van Hooff)

Maybe it was just the light that Mama needed to see at the end of her life. She died a week after her friend’s visit.

This is the way we should all end — not with a whimper, but with a howl of joy. And memories of love.

Watch the full video of their reunion below: