The 'Two-Minute Rule' prevents small tasks from piling up

David Allen's Getting Things Done (2001) introduced the two-minute rule: if a task takes less than two minutes to complete, do it now rather than adding it to a list. The rule is counterintuitive — most productivity systems push towards batching tasks — but its power is in preventing micro-tasks from accumulating into cognitive overhead. Each item left undone consumes a small amount of working memory and creates a low-level anxiety Allen calls an 'open loop'. Research on the Zeigarnik effect supports this: incomplete tasks are recalled more readily and intrusively than completed ones.

Source: Allen, Getting Things Done (2001)