Purposeful Redundancy
The principle of purposeful redundancy is that we have to provide duplicates of things. It could be as important as charging cables, down to simple things like sticky notes. Reinhart was inspired by NASA’s engineers who made multiple backup mechanisms for their space rovers, because sending then back from space for maintenance is very expensive.
We use redundancy as a method to anticipate technical failures, and to immediately accomodate for overdemand. For example, when going to vacation, Reinhart brought in a lot of charging cables and adapters, split between luggages and bags, as a backup when one of these was lost, and to quickly supply when his family needs to charge more devices for a short time.