“Earliest tech memory? Playing with my Dad’s LED tester. His job was in LED R&D back in the 1970s so we had a big heap of spare LEDs lying around, and a clever metal black box you could plug the bulbs into, flick a switch, and hey presto, the bulbs sprang into life.”

(My response to the Guardian technology blog question ‘What’s your first tech memory?’ in the run-up to Rob’s 70th birthday on the 26th. He even co-authored a book on the subject, Williams, E. W. and R. Hall. Luminescence and the Light-Emitting Diode. Pergamon Press, 1978.)

My first memory of a coincidence was playing with a fire engine as a 4-year-old outside our starter home in Danbury, Essex, while firemen raced into the kitchen to put out an oven fire started by Diane. And now I’m back in Essex again (the less posh end).