I asked my grandfather about this once. He said that before ~30, beer tasted like piss, but after that, something changed. I think it's about the body adapting to the world, if you can say it like that.
Might just be acquired taste as well. It's a pretty well-known phenomenon, though it primarily applies to sour and bitter foods. There can also be a number of psychological reasons, mainly caused by the way drinking alcohol is perceived in society.
@LilRora That acquired taste is why i don't go near alcohol,it easy to get addicted even when you drink responsibly.