I used to carry 2-3 knives all the time, for varying reasons. Beater knife, fine-edged knife, left-handed knife.
I just carry one knife at a time these days, but I have a work knife (Nura 3.5), a fancy knife (Protech Maple Burl Godfather), outside-of-work / when my USMC vet boss is closing the store knife (Kershaw-Emerson 4KXL), my knife that will be my EDC in most situations come November (ProTech TR4.1, autos are legal in OK in two weeks! Thank you, Mr. Ritter), and my ridiculous feeling-awesome knife (Cold Steel Large Polished Espada, soon to have a DLC XHP blade swapped into it.)
I also have a Brian Evans Companion fixed blade on order, which will likely become something I carry literally every day. Additionally, I just bought a Cold Steel Pro Guard off of the JerzeeDevil exchange, which I'll probably carry when I'm not working.