Most beers, being perishable goods, aren't really designed to hang around for a someday pour. The hops start to fade and the quality degrades. "Born on" dates and such (remember 2009?).
While home brew and other freshly bottled beers peak in flavor 2-3 months, others (not unlike most people I know) mature with age, improving over time in character and complexity. Particularly barrel-aged versions, barleywines, lambics, Imperial Stouts (and so on).
Admittedly, I've not had the






