To dream of your age signifies you anxiety and concern of growing older. It may also represent some regret or failure in your endeavors.
To dream that you are older than you really are signifies wisdom. Perhaps you need to be more sensible. Negatively, it may mean your unyielding ways and rigid thinking.
To dream that you are younger than you really are suggests that you need to be more carefree and be young at heart. Live a little!
If you are a parent and dream that your child is younger than he or she really is, then it means that you are longing for the past. Perhaps you feel that you are no longer important and wish to regress back to a period where you were more needed. Time is passing you by.