The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
Some of the old farts carry a fungal patch of Amadou on their vest to pat dry their flies after a few casts to spring them back to life.
I can produce a source for generic fly drying powder on demand. PM me if you're interested. It's called hydrophobic fumed silica
I hope none of you are with the IRS.