Fridge life of beer

We bought a bunch of random beers a few years ago for a party and have some left in the fridge. I opened an IPA tonight with a May 2015 “enjoy by” date and the beer tastes great. We popped open some other brands / styles, all with the same result. Is this typical or did we just luck out? I’ve suspected for some time that these manufacturing dates are simply to convince you to consume faster, but not sure. Can beer age like wine?

Marketing ploy.

Some beers can age - others not so much. The aging of beer is very temperature dependent, so beer kept in a refrigerator will keep longer (roughly 4-6 times longer) than beer kept at room temp.

just depends on the beer like Rick said. Some IPAs don’t have a noticeable difference cause they aren’t hop forward to begin with or are pretty malty to start.

The same things that impact wine will impact beer - heat, light, vibration and age. Hop oils are pretty volatile so those flavors can fade quickly when in unfavorable conditions.
With the exception of the Belgian lambic style beers, generally the darker the beer, the longer they will keep.
I got to try a Sierra Nevada and Dogfish Head collaboration beer last week that was made in 2009. It was a strong ale in style, but was as black as a stout and was totally delicious.
I’ve never had a really old lambic, but I have heard of them tasting great with decades of age.