Registration numbers (number plates) you've never forgotten

UGB507 - The first car I ever steered. Can’t actually say drove as I was only 11 and couldn’t reach the pedals so my brother (who’s car it was controlled them whilst I steered the car). Drove/steered it to school, which was about half a mile away, and waved to the teachers who were walking along the road from the bus stop whilst my brother ducked down out of sight. 5 minutes later I’m in the headmaster’s room getting a dressing down as he thought I had stolen it.

59RN91 - The reg no of the car when I chauffeured an Admiral about during my time in the Royal Navy.