You don’t have to forgot about your petition. Just don’t overly dwell on it. Think about it like ordering something via the internet. You know it is on it’s way so just get on with your life. When it comes to mind, it is fine to think about the petition itself but try not to get lost in a never ending loop about the result.
By the way @The_Evil it is a rule of this forum for new members to properly introduce themselves so please click here and tell us about yourself and any experience you may have in magick, such as what you practice, how long you have practiced, areas of interest, etc.