My physio is always late.

Pretty much every session.


He's not lazy. He's not inconsiderate or unprofessional.

He falls for planning fallacy

This is a bias that says people tend to underestimate how long it will take them to get stuff done. When he says just five minutes it’s actually ten. A day of five minute chats that take double the time is twice as long.

He’s also an optimist.

He believes when Google says a journey is 15 minutes it means 15 minutes. Why would Google lie? He doesn’t consider that traffic happens or he might not find a parking space straight away. He leaves 15 minutes for the journey because he’s gunning for the prognosis to be true.

Planning fallacy plus optimism equals lateness. Again and again.

The next time someone is late for you, ask if they would say they were an optimist. Ask if they have heard of planning fallacy. You may just blow their mind, and stop them being late for you again.