Habits as a mental LFU Cache
A discussion of improving day by day and taking advantage of life’s compounding effects is not complete without including habits. Habits help us constantly improve, but more importantly, achieve that improvement on auto-pilot, making long term consistency possible without much mental strain. This amazing ability of the human brain to rapidly recall such habits reminds me of an LFU cache (pronounced cash) in some ways. But first, what in the world is an LFU cache?
Simplified, a cache is a term often used in the computing world to describe
a hardware or software component that stores data so that future requests for that data can be served faster
The whole point of a cache is to make information retrieval as fast as possible, because data can exist in storage from which extraction is resource heavy. If you’ve ever purchased bulk goods from Costco and took a few items out to place in commonly used spaces like a pantry shelf, counter, or fridge, you are leveraging the power of caching by making it easier to retrieve these items. Your web browser caches commonly used websites and corresponding data - sometimes you will notice well frequented pages load much faster (and include more of your data) than novel ones. A common metric for deciding what to store in a cache is just by retrieval frequency; the more often you retrieve something, the more it can benefit from being stored in a cache. Also, a cache by definition has to be constrained in storage capacity, otherwise the benefits diminish. Imagine you storing your Costco items in a warehouse - that defeats the purpose of having a much smaller fridge/pantry to easily retrieve your items from!
So too does the brain cache frequently encountered thoughts and behaviors. Theres a reason that things you think about or do more often become so easy to retrieve from a mental cache that they become automatic. As Robert Cialdini would say, that is the brain’s click-whirr automatic processing occurring. The interesting thing here is due to our biological makeup, our brain’s cache comes pre-loaded with behaviors related to survival (for good reason). These behaviors sometimes lead to cognitive biases. The rest of the brain’s cache can be filled with habits, which if beneficial, can create automatic improvement.
However, they have to “make it” to the cache in the first place. Using the metric of retrieval frequency, this means that consistency of behavior has to reach a certain threshold to take a slot in our cache. This is why sometimes just a couple days of building a habit followed by a subsequent halt are meaningless - the habit won’t make it to the cache! But say the threshold is met, and the habit makes it into the cache. How does it stay there? That’s where the LFU comes in.
LFU is simply an acronym for Least Frequently Used, one of the metrics that describes how to remove items from a cache once it has reached capacity (you can use least/most recently used, smallest, largest, etc). Since cache storage is limited, the brain has a clever way of clearing (or intentionally forgetting) less frequent/important items. If your habit isn’t deemed as important enough, it will be cleared, and you will notice it will be much harder to continue the habit afterwards. But as consistency increases, the cached habit will be much harder to remove - definitely a good thing for beneficial habits.
If you can focus on consistently doing valuable activities, you will hit some threshold at which it requires much less effort to continue doing these activities (they’re in the cache!), resulting in a continuous push of your personal flywheel. The brain already takes care of fast retrieval using efficient memory caching - you just have to make your habits important enough to get there.