You're not, Heathrow Dir...just mature
Remember when the firemen counted the edge lights from the fire vehicle at the side of the runway! I'm afraid I do.
At Aldergrove last century only Rwy 17/35 available at night, a we bit foggy and a Herald ( Aaaah) trying to land. He needed ( I think) 1100m RVR.
Runway was just reopened after resurfacing. Firemen call number of edge lights seen and this is transposed into RVR and passed to pilot.
Visibility improves... 14 Lights seen...RVR 900m....
Visibilty improves...14 lights seen.....RVR 900m...
Met Vis 2000m.......14 lights seen....RVR 900m...
etc.
Luckily pilot had discretion to use factorised Met Vis and landed.
You may have guessed by now, runway had a hump in it and when resurfaced the edge lights were correspondingly lower than previously....you can work out the rest!