It is entirely possible that someone forgot their login and thinks it is the one you have, and they are simply asking for a password reset. It is also possible that someone is trying to do no good. If you are getting the notifications, they are not very good at what they are trying to do. You shouldn't worry. I won't warn you to change your password, because they aren't getting in. Some people automatically tell you to change everything when something like this happens, but it is usually a complete waste of your time.