There was endless late-night speculation in my undergraduate days as to who might get the “tap on the shoulder” from an anonymous representative of the security services in a bowler hat that would signal an invitation to embark on a career as a spy. The qualities we imagined were required were all drawn from John le Carré novels and James Bond films – a certain suave detachment, patriotism mixed with a dash of amorality, and, of course, a love of fast cars. But I don’t recall dyslexia or Asperger’s syndrome ever being mentioned.