Why? There are plenty of reasons for this, some of which are more easily overcome than others. The most fundamental obstacle is in fact our ally, used properly: we are designed to operate out of habit. If we weren't, our lives would be nightmarishly difficult. We wouldn't be able to walk or tie our shoes without concentrated effort if it weren't for our ability to turn conscious physical and mental work into unconscious and effortless activity. The problem is that our capacity for forming habits is indiscriminate; that is to say, it works with whatever repeated thoughts or behavior we feed it. If you get "addicted" to exercise, then exercising will feel natural and not exercising will leave you feeling awful. If you eat good food, then a trip to a fast food restaurant will leave you feeling nauseous; if you regularly eat at such establishments, on the other hand, then that's what your body will learn to crave. Thus habits, once formed, are hard to break, which can be good or bad. It's bad if you're trying to quit smoking, but good when it comes to the overwhelming majority of our day's actions (washing, walking, getting dressed, driving from point A to point B).
It's both good and bad for our chess, too. It would be horrible if we had to go through some sort of ridiculous checklist before every move. ("Am I in check? Is my opponent in check? Are any of my pieces threatened or threatening anything? Is he threatening checkmate? Do I control any open files with my rooks? Can I double my opponent's pawns? Do I have more mobility?" And so on, ad nauseam.) Most of the time, for an experienced player, this is all understood more or less automatically over the course of the game. If we've developed certain misunderstandings about the game, though, we'll carry them around like baggage too, and they're not so helpful.
OK, back to impediments. The first was the basic nature of the habit-forming process. Second, our resolutions tend to stay at the level of wishes. What's necessary, if we want to give non-trivial changes their best chance to succeed, is to form a plan for implementing the change. For example, let's say your goal is to gain 100 rating points this next year. If you're not new to the game and not a kid, that's not so easy, so it's a very good goal: ambitious but not insane. Given that sort of goal, what should you do?
The first thing you should do, of course, is hire me for lessons. (That didn't really need to be said, did it? Well, maybe it did. Moving on...) Half-jokes aside, what you should do is to break it up into subgoals. You might want to break that up into quarterly subgoals - say, to gain 25 points every three months, or if you think that getting back up to speed the first couple of months is necessary, then stagger it a bit. Maybe you'll try to gain 10 points by April, 40 by July, 70 by September and 100 by year's end.
Next, you need means to implement these goals. What are you going to do to make it happen? How much time can you reasonably set aside to study? If you want to gain 100 points but can't spend more than an hour a week studying, it's not going to happen (unless you're starting off with a very low rating). Let's say you have enough time and have the chance to play in tournaments on a regular basis. What's your study plan? Here it's crucial to choose well, as there's no sense spending a lot of time on activities that aren't going to benefit you very much. (A couple of hours of online 1 0 and 3 0 every day will do very little for your chess, sorry.) Making a concrete plan to implement the goal is necessary, otherwise it's only a daydream, an idle wish.
It's easy to get motivated this time of year, but what will you do when the motivation flags? You play in a tournament and lose 20 points, or you get sick for a week and break your training schedule, etc. Something happens, and you're out of your zone. What then? You can always wait until New Year's eve/day 2010, but life will race by if we keep waiting until next year. So think about that, too. One way to help yourself stay on track is by getting a training partner, optimally someone who's pretty close to your own strength. Sure, it means you'll have a tougher time preparing to play him at the next local tournament, but you'll benefit so much in every other respect that it's more than worth it. Mutual encouragement and accountability is invaluable.
There are other good ideas for making resolutions work, or at least giving them the best possible chance to succeed, and maybe some readers can offer their own suggestions in the comments. I hope some of these ideas help my readers, though, and not only with their chess. And if you do have some chess goals for the new year, goals you're willing to work on and admit, maybe you can write those in the comments, too, and then look back a year from now and see how you did.
Happy New Year, everyone!