The insane ritual Tim Cook goes through every time he visits an Apple Store

Tim Cook has revealed the crazy lengths he goes to in order to surprise staff at Apple Stores around the world.

Cook sat down for an interview with The Telegraph in London, and the newspaper accompanied him on a visit to Apple's sprawling Covent Garden store.

The problem is that Cook is so famous, so well-liked by staff that scheduling a visit ahead of time would likely cause chaos. Word would get out. The store would be mobbed. Business would grind to a halt. The press might show up.

So the only person in an Apple Store who knows about a visit from Tim Cook ahead of time is the store manager.

And he cannot just walk in through the front door of an Apple Store. Instead, he surprises staff by entering through the back door. None of the blue-shirted staff have any idea that he's about to emerge from the back of the store.

For his visit to the Covent Garden Apple Store, Cook arrived early in the morning, during the "Morning Download" staff meeting. That meant he had time to talk to staff and answer any questions they have about Apple. The staff there broke into a spontaneous round of applause. Then they surrounded him, shaking his hand and taking selfies.