Some skills are like learning to ride a bicycle. Everybody knows how it is impossible to forget how to ride a bicycle.
But most others need regular practice. Or else, they slowly evaporate from our brains. When we do not speak a language for several years, it slowly fades away. We need to train regularly to run at a particular pace. All of these are quite evident to us.
And then there are certain qualities. They seem like bicycle riding, but actually require constant renewal. Such qualities include the art of making good conversation, the ability to listen to other people and even qualities such as empathy and compassion. Chris Voss, a former FBI hostage negotiator, talks about how we lose our negotiation skills without our conscious knowledge, if we do not practice them regularly.
In all these cases, it helps for us to revise and refresh those qualities once in a while. To reread books that have taught us and revisit some of our most valuable lessons.
We would never forget how to ride a bicycle. For everything else we hold dear, it helps to have constant reminders.