The date could affect it, depending on the storage. Young's isn't terrible, but not a great example (IMO).
I love British beers, but it's hit-or-miss in the states. My local haunt used to carry Fullers (pale and porter were my 2 fav's), and I and others regularly purchased it... fresh and yummy. I picked up one a year ago from a different locale, and I actually dumped it. Stale, old, terrible.
I have rarely had good experiences with imported bottled beers. Most places do not know how to store it or handle it. Youngs Oatmeal only has 5.2% ABV, so it's not going to age well regardless. In this case I'd say it's the beer and not you.