I like to say that mutable state is to software as moving parts are to hardware (https://kristiandupont.medium.com/mutable-state-is-to-software-as-moving-parts-

I like to say that mutable state is to software as moving parts are to hardware (https://kristiandupont.medium.com/mutable-state-is-to-software-as-moving-parts-are-to-hardware-dd53303a97cd https://kristiandupont.medium.com/mutable-state-is-to-softwa...). It's not always the best (or even an) option, but it does spare you some concerns.