I created a MySQL RDS instance. When I connected to this instance using the master user which I specified when creating this instance, I realized I do not have DBA role and obviously I do not have the permission to make this master user the DBA. This produces all sorts of problems. Why can't I be the DBA? Don't I own my own AWS account and my database?
RDS is a service. The user/password you choose when you created is the "admin" account that can do things like create databases and create new grants. So try that user.