Where you were last Friday night is also a fact, and even if you were somewhere in public most people would consider that personal information.

Same with your age, your gender, your height and weight, your address, your phone number, where you work, etc.

All could be either measured in public or are likely to already be in a public database somewhere.

Yet most would consider those to be personal information.

That information might not be private, but that doesn't make it any less personal.