I think the Chimay beers seem particularly sensitive to handling and storage issues. Some of the most disappointing bottles I've ever opened were Chimay, especially the Red.
We had the good fortune to visit the cafe at Chimay last year. All of the beers were phenomenal! Plus, the Blue they served us was properly matured (about 6 months old). We also visited In De Vrede, the cafe for Westvleteren, and their beers were so fresh that they were a major disappointment. No real character at all. None were more than a few weeks since bottling.
I also learned that Cinq Cents (White) is different in kegs vs bottles. The kegged beers have additional dry hops, although it's unclear whether there were dry hops still in the keg. I had one at a beer dinner in Antwerp that just blew me away! It had just as much hop flavor and aroma as many of the newer Belgian-American IPAs have. That was also where we learned about the additional hopping for the kegged beer.