‘He’s nearly there,’ Mrs Bush revealed at the Bush ranch in Crawford, Texas, where the family have been living since leaving the White House in January. ‘I think the penny may finally drop in the next few weeks that he isn’t the leader of the free world any longer.’

Mr Bush, 62, first showed signs of noticing that something was up in late February, when Mrs Bush says he asked her where ‘the nucular codes box’ was, referring to the briefcase which had been carried around behind him by a Secret Service agent every day for the previous eight years.

‘Then in late March we had a call from Condoleezza Rice to say hello,’ Mrs Bush added. When her husband asked why he hadn’t seen any of his Cabinet members for three months, a convenient excuse was found, she admitted. ‘We told him that Dick Cheney had shot them all and they were in hospital. Otherwise it would all have been too much too soon.’

More recently, Mr Bush has taken to standing forlornly in the corner of his lounge at home in Texas. ‘At first we thought he had gone a bit nuts like Cheney,’ his wife said. ‘But then we realised that, deep down, he was beginning to notice that he hadn’t been in any oval rooms for quite a while.’

If Mr Bush does cotton on this summer, as his wife seems confident he will, then he will have made significant progress since 2001, when it took him more than a year to understand that he had been elected president.

‘When we first moved in to the White House and George hadn’t realised what was going on, that Al Gore just got madder and madder,’ said Mrs Bush. ‘So at least this new guy doesn’t really care what George thinks. Which is funnily enough what a lot of people have been saying to me for a while, actually.’