Beer

Ever have a beer that tastes of old sweatsocks?  Beef broth? 

A beer you have had before and was great then?

If you can, try to determine when the beer was bottled.  It might be on the bottle, six pack, or case.  A 'best before' date means it was bottled about 3 months before that date.

Or was the beer left under the lights at the store outside of the opaque corrugated cardboard case?

Old stale light struck beer.  Avoid it.  For maximum enjoyment.