I recall once, while on a few days leave, talking to a pilot friend who regularly overflew the place where I was valid. He went over a long way up but nonetheless suggested he give me a call on the tower frequency. "What's the frequency?" he asked. I couldn't remember!!!!!!!! So I'm full of admiration for folk who can retain frequencies in their heads from the early 80's!!!! (Strangely, as soon as I'd put the phone down it came back to me.....)