Of all the questions we ask about our minds, "why can't I remember?" is perhaps one of the most frequent.
Andi Bell can memorise hundreds of cards
A new BBC television series, 'The Human Mind' sets out to find an answer - and for tips it turns to one man for whom forgetfulness is not a problem at all.
Andi Bell has ten shuffled packs of playing cards placed in front of him and is given just 20 minutes to memorise the order of every single card - all 520.
When he is tested, Andi - the 2002 world memory champion - correctly remembers the position in the packs and the value of every single card he is tested on. So how does he do it?
Andi's technique is an unusual but simple one. Long before taking on any memory challenge he walks past a set of London landmarks, establishing the route firmly in his mind.
He might start at the Houses of Parliament, before continuing to the London Eye via Westmister Bridge.
But that's just the first stage. The second involves using a bit of imagination.
"When I memorise a deck of cards, I turn each card into a picture and this is a colourful animal or object that I've learned to associate with that particular card," Andi explains.
The jack of clubs might become a bear, the nine of diamonds a saw, and the two of spades a pineapple.
Andi then puts the two stages together, creating a bizarre journey with a cast of colourful images and characters. In his mind he imagines walking around London on his route, placing the objects in groups of three at particular landmarks.
At the Houses of Parliament for instance, he imagines the little bear with the saw and pineapple.
When it comes to recalling the cards Andi simply retraces his London route in his mind, visiting various landmarks and remembering what he has placed there.
It sounds far-fetched, but Andi claims anyone can use this method to remember vast amounts of information.
"As a child I had a conventionally good memory. But once you learn a technique like the location technique it takes everything beyond what you can do naturally."
In fact, Andi's method is not new. It is a variation on the so-called "Method of Loci" first described by the Greek scholar Simonides in 500BC.
Could you learn the sequence?
He was the first to realise that you could hugely boost your memory power by using a well-known location - in Simonides' case a familiar room - to place things you wished to remember.
The reason the method works is because of what's happening at the tiniest level in your brain.
The building blocks of the brain are cells, called neurons. In each of our brains there are an astonishing 100 billion of them, connected in a massive network.
When we commit something to memory we establish a pathway through this network to wherever that memory is stored in the brain.
But the trouble with creating a single pathway is that if - for whatever reason - it gets broken then that memory cannot be recalled.
And that's why the Method of Loci is so successful. It creates not one pathway through our neural network, but many such pathways.
If one pathway gets broken, there's always another to take its place.
A familiar location, for instance, will be known to us visually - by our memory of what it looks like.
But we might also have a neural pathway in our brain which represents the location's smell, or a pathway which represents memories of an experience we have had there.
If we can "tag" new pieces of information to these locations, which already come with so many well-established pathways, it becomes very hard to forget them.
The first episode of 'The Human Mind' will be broadcast on BBC1 at 2100 BST on Wednesday 1 October.