You don't know where your time goes. You just think you do.
Peter Drucker's fix for time management wasn't a schedule — it was catching your own memory lying to you.
Drucker used to hand executives a private exercise: guess, on paper, how you split your week. Lock the guess away. Then keep an actual log — every call, every meeting, every interruption — for a few weeks, and compare.
He told the story of one company chairman who was certain he divided his time evenly among his senior staff, his top customers, and community work. The six-week record showed something else: he'd spent almost all of it acting as an informal dispatcher, phoning the plant about orders from customers he personally knew — orders that were already moving fine without him. His secretary showed him the log twice before he believed it over his own memory.
Drucker's point in The Effective Executive (1966) wasn't to shame anyone. It was that people reliably remember spending time on what they know they should be doing, regardless of what they actually did. Memory edits for self-image. A log doesn't.
Most time-management advice starts with a calendar. Drucker starts with evidence. You can't cut the fat from a week you haven't measured — you can only cut the fat from the week you imagined.