When I started fly fishing at the heady age of 10, I only had two fly patterns, Sweenty Todds amd Missionaries.
The chap in the tackle shop said, "Black for dull days, white for bright"...and for years thats about the only two flies I used. (until I found Bitch Creek Nymphs
).
I know I am not in the same league as you lot, but I tend to carry a dark and a light F-Fly, a dark and a light spider of some kind, the same with nymphs and the same with streamers.
No particular pattern, just shades and sizes.
Howver, my fly boxes at home are full of all sorts of fly...but they are not my fishing boxes!