How many knives does a person
need? Well, that depends on what that person does and what they use knives for. For many people's basic EDC cutting tasks, one good folder could be sufficient. But there are still reasons to have other knives. Some reasons could be that if you sometimes travel to a jurisdiction that has stricter or different laws, you might need a different or smaller knife for that. If you want to carry a substantial blade for serious tasks, but are often around sheeple it might be a good idea to carry a smaller, friendlier blade so they don't get scared by the serious one, but you still have that in case you need it. If you carry for defense, there are reasons to carry more than one knife, e.g., one strong side and one weak side, or one (or more) for utility and one (or more) for defense. Sometimes you also want to have more knives on hand for people who don't carry their own. I've been camping with people who didn't bring any knives. Since each person should have at least one, it was a good thing that I had a few extras, so I could give my buddy a knife to use and I wasn't left without one. A few years ago my mother told me that she was at work and needed a knife to cut something but no one had one, so she asked me for a knife to keep in her purse. It was a good thing I had an extra knife, so I could give her one and I didn't have to go knifeless. There have been other circumstances where a friend of mine wanted or needed a knife and I could loan one out because I had others. If you want to carry different knives for different occassions (e.g., dressy knife to go to a wedding, serious cutter for camping, stainless for food or fishing, different shapes for different types of cutting, etc.), then you need more than one knife. If you carry a SAK or multi-tool for the dozen tools on it that are not a knife, you're still carrying the knife in it in addition to the dedicated knife (or knives) you're carrying, so your "blades on the body" count goes up inadvertently. If you're a collector, by definition you'll acquire more for for your collection. Whatever you use knives for, eventually a new knife will come out that will serve your purposes better than what you currently have; at that point you may not
need the better knife, but you'll have a very good reason to buy it anyway. It is possible for knives to get broken, lost, stolen, confiscated, etc., and having more will ensure that you're not left knifeless if something happens to one of your knives. So even if you only need one, you may need more than one to make sure that you always have one. I always carry more than one pen. I never need more than one pen at a time, but I carry more because I have lost pens and didn't want to be left penless when something happened to one of my pens.
You ask how many knives a person needs, I know people (you might know some too) who don't own a single knife, and they don't have a problem with that. How many knives do those people need? I own lots of knives, and still find reasons to want (and, when I can afford it, to buy) more. Necessity is hard to determine, but you're here in the company of knife knuts who have lots of knives and want lots more. Ask this question on a different forum and you'll hear very different answers.
Try asking on
a computer geek forum, or on
a watch forum, or on
a lesbian forum, or on
a flashlight forum, or on
a political forum, or on
a druggie forum, or on
a vampire forum, or on
a christian mom forum, or on
a BDSM forum, and you're sure to get very different responses, though even at those places the most likely people to answer are the knife knuts there so you'll still get a biased response. Actually, if anyone's got the time and energy, I'd love to see someone go to all those forums and post the question, "How many (non-kitchen) knives does a person need? And how many do they need to carry at any given time?" and post links here to the particular threads so we can follow them.