When you create a Story, you are automatically assigned as the Requester. You can change the requester in the Story dialog if you would like someone else to be credited as Requester.
Requesters are automatically added as Followers, which are users who receive all notifications of changes in Story status.
If you no longer wish to be a Follower after changing the Requester, remember to de-select your name from the Followers dropdown.
Whenever you add a comment to a Story, you will be automatically made a Follower of the Story, if you aren't already.