Philosophy, claimed Aristotle, begins in wonder. The same holds true for love of wine. No vinous experience, for instance, is more profound or seminal than one that prompts the thought, “How could this come from grapes?” A disparate clutch of wines recently tasted aroused wonder of quite a different sort, revealing some widely held distinctions to be as fluid and inscrutable as the wines that called them into question.

Thanks to philosopher-turned-wine journalist Gian Luca Mazzella and generous members of Germany's VDP, an extraordinary 100-year retrospective of Riesling was held at Schloss Johannisberg in April 2008 and, a year later (in honor of the grape's 350th documented year in Germany), an equally grand tasting of Silvaner at Schloss Castell. Most of the superlative Rieslings came from renowned sites in fabled vintages, bearing such traditional terms of approbation as Cabinet, Auslese, or Trockenbeerenauslese. The oldest, however, could claim no such distinction. The 1900 Ruppertsberger Stückelpfad of von Bassermann-Jordan grew in an average to good site and good year but-as witness the absence of Cabinet or Spätlese from its description-was not thought to be among its best wines. "We were surprised how good it was when we recorked it," said general manager Gunter Hauck. It was not just the quality of this brightly amber wine that surprised this taster, but the way it typified Ruppertsberg virtues for which one would look in a youthful exemplar: pronouncedly peachy, subtly creamy in texture, yet juicy, finishing slightly rustic, saline, and cyanic.

A 1915 Schloss Hallburger Silvaner from von Schönborn was scarcely less revelatory. True, the year is known as outstanding, but the site only as very good. It was neither a Cabinet nor Prädikatswein. It smelled like a field of flowers and grasses, and it was subtly creamy yet delicate and lemony-bright, its finish a rivulet rippling across stones, paradoxically arousing awe precisely because (like a 1934 from the same source) one could have-indeed, wanted to!-press it into immediate service at table, as if it were a contemporary. Ancient wines that demand to be judged by parameters we set for young wines remind us how far we are from comprehending vinous aging and how dubious we should be that any of today's will be this resilient.

They call into question, too, a divide of which wine lovers-this one included-are very fond, between good wines and great. It's hard not to refer to wine that promotes spine chills and wonder as "great," yet the pedigrees of these were not exceptional, and their prime virtues were the practical ones for which they had been crafted: deliciousness and staying power. Ample numbers of wines were on hand oozing complexity and proclaiming their terroir's and vintage's greatness, but these two were paradigms of goodness that had more than kept pace in bottle.

"Who knows how it will taste," remarked Erich Salomon in 1997, noting that 1956 was not an especially good year, and the wine at hand-grown in sand on the Wieden (once a prison yard), not on the Urgestein terraces above Krems-had turned up by accident in his cellar. Just a sliver of cork was intact, but out came pale green-gold essence of Grüner Veltliner, its vivacious display of beetroot, nutmeg, citrus, and white pepper leading to a suitably rustic and simple lunch being summarily convened: What else could one do in the face of a wine that good? (It graced the table freshly for half an hour.) Even great wine should still be delicious, and if one were forced to choose between great wine that taxed one's palate, one's memory, and one's vocabulary, or really delicious, good wine willing to testify to long ago, one's intellect might be conflicted but not one's appetite.

A "mystery wine" poured in Berlin in April 2007 stymied friends, all wine experts, though those who averred it might be Northern Rhône from the '70s "showing youthfully" weren't entirely off base: The wine had at least grown on granite. It offered sage, mint, smoked meat ("Côte Rotie"-like?), coffee, and black walnut; deepened in color with air; and above all was fruitful and fun to drink for a half-hour or more. Fun, no doubt, was just what Sichel & Fils Frères envisioned when they bottled this Fleurie in Geisenheim. By the next vintage, fun was in short supply worldwide, amid the Great Crash. This points up a benefit of such wines: near certainty that they're for real. No one forges a Beaujolais from 1928, labeled in German and French!

Surely that's also true of Château du Mont ("anc. Château St Paul," Médoc St Seurinde- Cadourne-none who tasted it knew of this château), whose 1889 was opened this spring. It came from a wine drinker's cellar, not a wine investor's. Its dried cherries, strawberries, cocoa, iodine, and undergrowth survived for hours. And a 1906 Bourgueil kindly opened by Pierre Breton (whose grandfather made it) when it was 100 years old was hauntingly fruit-filled (but fleshly, not ghostly) and neither maderized nor acetified.

Do we overrate vintage, high-priced terroir, grape, and pedigree? Do we underrate goodness and deliciousness, quite forgetting that levity and straightforwardness don't preclude long aging or awesome vinous testimony? Do old wines make fools of us? Yes. What should this teach us? Resist sharp dichotomies. Be humble and savor lip-smacking perplexity. You'll miss out on less fun and wonder that way.