The main problem with adding your own page is ensuring that the “no original research” rule is followed. In principle, everything on Wikipedia should be verifiable by third parties so they can check it. So if you write an article about yourself and say “Their dog’s name is Chesterfield” there needs to be some kind of external source that other editors can use to check whether that’s true. People writing about themselves often overlook that sort of thing. A classic example is a problem Philip Roth had trying to correct a Wikipedia article about a book he’d written, Wikipedia can’t simply “take his word for it.”

The other major problem is the “neutral point of view” rule. It’s very difficult to write about yourself in a neutral manner so it’s a safe assumption to scrutinize the neutrality of one’s own edits about oneself very closely.

Probably the best way to go if you’re notable is to ensure that you’ve got a detailed biography of yourself published somewhere and then point Wikipedia editors at it. And don’t get possessive about your Wikipedia article, it’s likely going to end up saying something you didn’t want it to say and there’s not a lot you can do about that if it’s within their rules.