I don't generally care if another human "coincidentally discovers" otherwise personal things about me. I think almost everyone has "information" they want kept private, like pin numbers or passwords.

In general I prefer to stay as private as possible because a) I don't actually know what my data could be leveraged for, neither today nor decades down the road, and b) privacy is a one-way street - data is private and anonymous until it's not, and then it never is, ever again.

For instance I don't feel a third party should be able to access my health records without my explicit permission for the purposes of denying e.g. employment, insurance or some other service or benefit. My country has laws in place to protect my health records but that could change at any time. Also people don't always follow laws, and the Internet is worldwide, not nationwide.

I also care about privacy as a consequence of liberty. I love that it's your choice not to be private, and I feel very strongly it should be a choice. You should never be compelled to reveal information you want kept private unless it's absolutely necessary to protect the rights of others. For instance a murder suspect, in a case where a sufficient legal standard has been reached, should be compelled to provide relevant evidence for the purposes of solving the case.

I do care about privacy, but I care about other things too, and I try to reach a compromise out of them. Sometimes the compromise means that I'm losing a tiny bit of privacy for the sake of a lot of something else, or that I don't do something else for the sake of my privacy.

However, I feel like this should be a personal decision. Some people like the OP might put a higher value on those other things than on their privacy, and that is completely OK, as long as OP decided this for themself instead of someone else doing it. And for that people in general need laws and tools to protect the privacy of the people. It's the same conclusion as @kadu reached, through other means.