A checklist is a written list of tasks, items, or steps that need to be completed or verified. Each item gets marked off (usually with a checkmark) once it's finished. Pilots use checklists before takeoff to ensure they've checked every critical system. Surgeons use them before operations to confirm they have the right patient, procedure, and equipment. You might use a checklist to pack for a trip, remembering everything from a toothbrush to a phone charger.

Checklists are powerful because they free your brain from having to remember everything. Even experts in complicated fields rely on them. A professional pilot might have flown thousands of times, but still goes through the same preflight checklist every single time, because memory can be unreliable when you're tired or distracted.

The beauty of a checklist is its simplicity: it breaks down big, complex jobs into manageable pieces. Instead of feeling overwhelmed by “clean my room,” you might create a checklist: make bed, put away clothes, clear desk, vacuum floor. Each checkmark gives you a small win and shows your progress. Whether you're planning a school project, preparing for a camping trip, or organizing a birthday party, a good checklist helps ensure nothing important gets forgotten.