Shari, are you sure you are telling us your right age ? (Happy birthday, belated, by the way). How do you know about level in the bottle? Are you going to wine auctions ? We always have that in the catalogues and condition reports; it's the first thing that is mentioned.
As to the OP, storage etc is important but some wines age better than others, some are not at their best for years after bottling,some are extraordinarily long-lived;; some great Sauternes are like that, and fortified wines like port and madeira go on for many decades.