I try to do something nice for our anniversary, and my wife does, too. But more often it's something we plan together, like a weekend somewhere together. Though there are years where we do nothing for the anniversary, but that's typically a mutual decision, too. If I forgot completely, it would almost certainly because something huge was going on. I'm sure I'd catch no shit for it. Similarly if she forgot completely there would likely be a good reason. And even if not, who the fuck cares? We treat it as an excuse to fly to Paris for a long weekend without the kids. If that doesn't work out, we'll catch an opera in Chicago and get a room there for a night or something.
Anniversaries are not a big deal, but they're great excuses to get away and have wild, animal sex in a hotel in a foreign city.