In preparing for battle I have always found that plans are useless, but planning is indispensable.
Dwight D. Eisenhower
A good stoic observation related to control. You cannot control outcomes, only your actions. This relates to another saying, “Luck favors the prepared”.
To be a stoic does not mean that I wait passively for events to occur and suffer them in silence. It means that I prepare for events as best I can, yet do not curse fate when they do not go as anticipated, knowing where my control ends.