Some elephants might want to forget...
Hannibal supposedly finished one of the most audacious moves in military history, the crossing of the Alps in 218 BCE, with one elephant still alive and kicking (Romans mostly). African elephants are used to extreme changes in climate, however, snow storms and icy winds battering you on sheer cliff faces must have been something else. Good thing an elephant never forgets?
Well, if this elephant had survived Hannibal’s subsequent onslaught down the Italian peninsula and become the matriarch of a herd of elephants back in her homeland, she’d certainly have remembered to never traverse the Alps again. Elephants do indeed have excellent memories; remembering harsh droughts from years ago is key to ensuring survival amongst the herd. Research shows that younger matriarchs without knowledge of particularly severe changes in climate are much more likely to lose young calves from their herd, due to starvation or dehydration.
The difference between an elephant and most animals is age. They can live for 60+ years, so their knowledge needs to be stored in their long-term memory. Humans fall into the same bracket here; memories we retrieve from our long-term memory can be incredibly useful. My memory of being mugged in Vietnam may well now be distorted, but it has probably served me well in providing a precautionary blueprint for the last 17 years. A lot of our memories aren’t necessarily used for ‘survival’, but they do bring back strong emotions; just think of that time a smell took you back to an event, or music transported you to a place and time in your childhood. Elephants have this too, stories of elephants reuniting after years apart in euphoria are not uncommon. Carol Buckley, from the Elephant Sanctuary in Hohenwald, Tennessee, recounts a story of two elephants bellowing at each other in excitement, touching each other’s scars with their trunks. They had briefly crossed paths in the travelling Carson and Barnes circus years before this. That memory was encoded strongly enough that the elephants had not needed to think of each other in those interim years (I presume). Other memories will need revisiting, such as the location of water holes, or the smell of their herd members, because by retrieving this information the elephants will be consolidating the knowledge and making it easier to retrieve again when needed. This knowledge is often a matter of life or death.
I want to remember the latest in neuroscience research, every current England cricket player’s average, and what the main points were from that National Geographic article on exoplanets. None of this is essential to my survival (I guess exoplanets could be) but I now know how to encode this information into my long-term memory, which is useful if you want to recall anything you value. I follow a couple of simple steps: I make sure I come back to the knowledge by testing myself on it, and I keep doing this through the process of spaced repetition. Elephants do this too, and we like elephants.