Let's discuss obsession, in its many forms. 'Here it is,' says Tim Steiner, handing me his BlackBerry.
Steiner, co-founder of Ocado, the online grocery business, wants to show me an e-mail from a journalist recounting a recent meeting with Sir Terry Leahy, boss of Tesco. The e-mail tells how Leahy ended the session by cracking a joke - he'd managed not to mention Ocado all lunch.
'And then, of course, he had,' says Steiner.