Earlier quoted context omitted.
First, you switched from respecting peoples' privacy to taking notes, thinking, and having opinions. I even responded to your comment before you added the notebook in the park example. You probably also noticed that I put »thinking« in quotes. Anyway, it is not the act of having the information about other people that is problematic, it is the act of collecting, using, or sharing it. Do you think I should be able to…
I didn’t write the original comment about the notebook in the park, just FYI. And your examples are not all the same. If you’re in public, you have no reasonable expectation of privacy. So yeah, take all the notes about me you want. That’s entirely different from my doctor sharing my health info.
And while you personally may not have any expectations of privacy in the public, that is certainly not true in general for everyone and in every country. Here in Germany the constitutional court ruled just this week that having a dash cam in a car violates the privacy rights of the people you capture.
You are also generally not allowed to take photos of people in the public without their consent. It is not a problem if they randomly appear in a picture you took of a building or whatever, but you are not allowed to take photos were people are the main motive.