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They used to consider a puerh only properly aged at 50-100 years at least!
But it depends on how you're storing it. If you're exposing it to a lot of air, especially in a home with any mold, it probably doesn't maintain its flavor, and may also lose it's chi.
They say the flavor stops maturing in a place like San Francisco because the climate is never warm enough. But it will be preserved a long time at its current flavor there if you keep it away from mold exposure.

That means I can bequeath it to someone in my will!!

Thanks, @indigoocean.