General Confessions are normally done with some significant change in life like being ordained or professing religious vows, maybe getting married etc and are not something we are required to do.
If you are simply confessing sins which had been confessed in the past forgetting the numbers is not relevant as these sins have already been forgiven. You can’t have these sins re-forgiven.
DISCLAIMER: Catholic Answers has turned over the archive to Catholic-Questions.org and no longer owns, manages, or moderates the forums. For additional apologetics resources please visit www.catholic.com.