Elephants are the largest land mammals on earth, majestic and powerful, but also gentle, deliberate, and emotional.

So what about that old adage? An elephant never forgets. Is it true? Just how intelligent are elephants?

As it turns out, our friends in grey pyjamas are a lot cleverer than most people realize. Here are a few anecdotes that illustrate just how good their memories are.

Hohenwald, Tennessee is home to The Elephant Sanctuary, which provides captive elephants with individualized care, the companionship of a herd, and the opportunity to live out their lives in a safe haven dedicated to their well-being.

In 1999, an Asian elephant named Shirley was the newest arrival at the sanctuary. Jenny, one of the elephants already in residence, became inexplicably agitated when she met Shirley for the first time.

The two grey ladies felt each other up with their trunks – the elephant equivalent of dogs sniffing each others *ahem* hind parts – and Shirley became excited as well.

Staff looked on, mesmerized, as Jenny and Shirley began to vocalize together, cooing joyously about what was evidently some kind of reunion. Ive never experienced anything that intense without it being aggression, said the sanctuarys founder, Carol Buckley.

But how did these two elephants know each other? After doing some research, Buckley discovered that Jenny and Shirley had briefly performed together in the Carson & Barnes Circus for a few months. 23 years earlier.

Real talk: would you remember someone you worked with for a few months 23 years ago if you ran into them on the street?

From 1958-1961, there was a devastating drought in Tarangire National Park, which is home to a number of elephant groups.

In 1993, another drought struck the area, and the elephants were faced with a dilemma. Should they leave the park and search for water elsewhere? Or should they stay and wait it out?

Elephant society (yes, they have a society!) is matriarchal; groups are led by the wisest, oldest lady elephants among them, who are in charge of defending the young and seeing to the general prosperity of the community.

Scientists who studied elephant behavior during the 1993 drought found that those groups with matriarchs old enough to remember the 1958-61 drought left the park and found alternative sources of water. Those whose leaders were too young to remember it stayed, and suffered higher mortality rates as a result.

Since elephants can live to be 60 years old, an elephant grandmother is a wellspring of knowledge that can save the whole group in times of great danger.

Psychologist Richard Byrne of the University of Saint Andrews did an interesting experiment that demonstrates the strong bonds of kinship between elephants.

Female elephants were presented with urine samples. Some were from members of their own families, while others came from strange elephants they had never encountered.

The females consistently responded negatively to the scents of outsiders, making plain that elephants can track every member of their family by smell alone. (Makes sense, given the size of their schnozes.)

“Most animals that hang around in packs, such as deer, probably have no idea who the other animals in their pack are,” Byrne said.

There is perhaps a dark side to the exceptional recall of elephants: they tend to remember the mistreatment they suffer at the hands of humans, and sometimes they even exact revenge.

In 2013, an elephant was tragically struck and killed by a train in eastern India.

In response, other elephants gathered at the spot where their friend had died, and locals were forced to chase them away with fire crackers and drums. Then the elephants rampaged into a nearby village, damaging several homes and a schoolhouse in what can only be described as an act of retribution.

This should make humans stop and think about the damage we do to our fellow earthlings – both wittingly and unwittingly. Not out of fear of revenge, but out of empathy.

Elephants have feelings. They mourn. They get angry. They react much as we often do. They deserve our respect and protection.