Consider how much effort it would take to find out how to chop an onion each time: the angle to position the knife at, and how should you cut? Fortunately, our brains have evolved a way that we can store solutions to prior difficulties in memory.

There are two types of memories that we have. Working memory is more accurately described as a type of consciousness. We take in information directly from our surroundings, and working memory organizes it for the job at hand. It's our working memory that stores digits when we're briefly memorizing a mobile number or calculating the number of onions that have been sliced.

Working memory has a very limited capacity. At any given time, it can only retain or process seven objects. However, there is an advantage to this constraint. Imagine having every mobile number you've seen before permanently engraved on your mind.

Only a fraction of the things in working memory are transferred to long-term memory. This is the brain's massive knowledge repository, the long-term memory. This information is only transferred if it is deemed important enough.

Long-term memory is the area of the brain where information is stored without our knowledge. The information is stored there until it is needed. It's how we know tigers possess stripes and that we favor red onions with ease.

The recall process returns the knowledge to working memory, allowing us to become mindful of that again.

A nice analogy for long-term and working memory is computer RAM chips and hard drives. RAM, or Random-Access Memory, is where machines store information necessary to run processes, but for no longer than that. On the other hand, hard drives store really important data permanently. In fact, since humans' memories are such efficient systems for processing and storing information, early computer scientists took the human brain as their model and designed computers to emulate it!