So this person lives in a society where everyone is out for themselves, yet has shared the fire nonetheless for the betterment of society. Ignoring the anomaly that is selfless people...
Do you find it hard to believe that there are people who will take advantage of a person who does nice things?
You are not defending the right to distribute your fire. You are defending the right to ensure no one else learns how to make their own fires.
And then what of the people who are capable of gathering and discovering fire? Well, the latter is ruled out certainly. Hell, if you applied the state of modern copyright law to this analogy you wouldn't even be able to use fire if some selfish arsehat discovered how to make it first. Which sadly, is the case in the medical 'industry.'
Yes, because ensuring nobody else makes fires without compensating you for your original invention is the only way to ensure you'll be compensated for your original invention whenever somebody makes a fire. This is actually where the difference between patent law and copyright law is important*, because "how to make fire" is a piece of knowledge that should be handled differently from "the likeness of Luke Skywalker", due to the vast differences in the good they provide to society and the ways in which they are created. Your issue with the medical industry, for instance, is one of patent law allowing people to own patents on things that are absurd, and has nothing to do with copyrights, whose biggest problem is that they're enforced in stupid ways and exist for bizarrely long periods of time.
*For instance, trade secrets are a thing, and one I don't really approve of outside pure luxury goods. Filing a patent does encourage creativity by making your methods publicly available, in exchange for giving you exclusivity over their use for a period of time (which, as currently stands in the law, is probably too long a time, but again that's a problem with execution, not with principle). At any rate, the problem of other people who could have developed something is one largely reserved for patents, not copyrights (where, to my knowledge, proof that you independently came up with an idea is a valid defense).