It's not that difficult to work out why teenage boys are so forgetful and vague. It's because they're surrounded by adult men who behave the same way. There was all that drama when Tony Blair couldn't find weapons of mass destruction, and Vince Cable seems to have forgotten his party's promise to scrap university tuition fees.
So why am I surprised that my 17-year-old can't find his socks?
'I know it's here somewhere,' says my 19-year-old, sifting through a pile of old bus tickets and half-eaten chocolate.
Maybe it's my fault. Maybe I've got used to organising the men in my life. But I also wonder whether boys and men are perpetually vague about dates, times, awkward phone calls and clean shirts because they'd much rather be thinking about other things.
'When you say, coursework has to be finished by the end of the month,' said my teenagers' headteacher recently, 'girls think, right, I need to get organised. Boys think, the end of the month? Oh good - I'll forget about it till then.'
I do sometimes wonder whether the male brain is occupied with stuff I find completely baffling - trainspotting, perhaps, or Technicolor fantasies of life halfway between Middle Earth and a Quentin Tarantino bloodbath.
Or perhaps it's full of the trademark signs of male competition you find in magazines - girls, money, cars, sport.
Whatever's going on, it doesn't focus on practical arrangements.
'Will you be in for tea?' I ask my 17-year-old.
Oh, good. Got that one sorted.