François Audouze wrote:There is no sense to let age a wine for more than 50 years. Wines were not made for that.
But as some very old wines were not consumed for several reasons, the question is : when we drink those wines, is it too late ?
And in many cases, the surprise is incredible.
I have drunk in a blind tasting a Pontet Canet 1870 with one of the best sommeliers in the world. Trying to guess the year, he just made a mistake of 90 years !!!!
Francois, in general I would agree, with one exception: Vintage Madeira. The appellation laws won't even let it be released until it's 20 years old, and it may take another 30 years to teach it enough manners for it to be drinkable.

Vintage Madeira is nearly immortal.
One of my most memorable wine experiences was drinking 1929 Mouton-Rothschild in 1988. Until then, I really hadn't understood why wine aficionados go ga-ga over old Bordeaux.
Then there are masterpieces such as the 1983 Adam Albert Hattenheimer Wisselbrunner Riesling Spaetlese. While this wine was aggressively tart when first released, it was also very aromatic, fruity, and enjoyable. It continued to give pleasure over 20+ years, with no "dumb stage", only getting better with age. The last bottle, which I opened a couple of years ago, was like liquid gold. Giving pleasure over a 20-year lifespan--one can't ask more from a wine than that!
-Paul W.