This video of one man, an axe, and a cork tree will make you really appreciate the next time you open a bottle of wine. Filmed in Sardinia, which supplies 85% of corks made in Italy, you'll discover that it takes a strong back and a skilled touch to peel off large pieces of bark without damaging the tree underneath. Gambero Rosso has some details about cork trees:
Cork oaks live about 150-250 years. Virgin cork (or “male” cork) is the first cork cut, generally from 25-year-old trees. Another 10-12 years is required for the second harvest, and a tree can be harvested a dozen times in its lifetime. Cork harvesting is done entirely without machinery.
And when you're toasting with wine in Sardinia, you might hear someone say “Salude, trigu e tappu de ortigu!” Which translates to “Health, wheat, and cork stoppers!”
(If you want to see big strips of bark being peeled, jump to about the 3:27 mark.)