This is described in more detail here. Rather than waiting for the first flag to be positively handled, as soon as a user makes a flag, they should be able to see a history of the flags they have raised and their current status. Right now, if a user is making flags that get declined, they have no way to see that their flags were reviewed and rejected by moderators and which ones are still pending review and therefore don't have a way to learn. This would remove some of the mystery of the flagging system and hopefully allow users that want to improve their participation a way to do it.
This was implemented back in July 2015. The link to view the flag history is available on the profile page even if none of the flags have been accepted yet.