I agree... I have an unopened bottle of beer from 1975, just by looking at it I can tell that its "better with age" window is long gone. (Note the sediment buildup at the bottom)
I used to be into some crazy beer communities and every few months they would do a tasting and tons would come and offer up the craziest stuff they have. One guy really specialized in collecting old beers and I have a bunch over time. The oldest I can remember came from somewhere between 1900-1910. It was awful, but we still appreciated being able to try such a relic.