You can sometimes include a text box note on a page even when the note is owned by someone other than the page's owner. For example, you may have permission to include notes belonging to one of your groups inside your own personal page.
If you include such content, it will be updated automatically on your page whenever it is changed by the owner. If you want to update it yourself, you must do that through a page with the same owner as the note.
Alternatively, you may take your own copy of this content and then when you edit it, the changes will only affect this page.