Notebook margins used to be a practical necessity—binders, holes, corrections. Now they are a choice. Choosing a wide margin is choosing room for afterthoughts, doodles, and the one word that arrives late.
Calendars borrowed the metaphor badly by filling every cell with color. A day without margin is a page without side space: you cannot annotate the plan when reality edits it.
We are not anti-planning. We are pro-legibility. A plan you cannot revise becomes a mural, not a map.
If this essay feels obvious, that is all right. Obvious things are often the first ones erased when people panic.