At 13 months my granddaughter discovered something remarkable. She stood between a curtain and a bed and noticed that a ray of sunshine came through the window onto the bedspread. So she closed the curtain and saw that the sun rays disappeared; then she opened the curtain and noticed that the sunshine came back onto the bed. Back and forth she moved — light, no light, depending on what she did with the curtain.

At small and large conferences I have recently addressed I showed this short video and asked the audience: what scientific principle had Zara just discovered? Perhaps not surprising, none of these accomplished people could come up with the answer, except for a Werksmans lawyer at a company breakaway. Cause and effect, of course.

BL Premium

This article is reserved for our subscribers.

A subscription helps you enjoy the best of our business content every day along with benefits such as exclusive Financial Times articles, ProfileData financial data, and digital access to the Sunday Times and Times Select.

Already subscribed? Simply sign in below.

Questions or problems? Email or call 0860 52 52 00. Got a subscription voucher? Redeem it now