|My thoughts exactly|
It seems to me that another way goals can become a double-edged sword and accidentally limit one's efforts is by way of the timeframes we attach to goals. People naturally think of personal goals on a one-year timeframe, but why stop at one year? With my goal of starting to learn a new language, I'm purposefully saying "Take one course," but realistically this is only a starting point for something that will take numerous years before there are really any results. If someone sets a goal for a year, does that mean at the end of the year they should quit on whatever they've started? On the other hand, it is true that breaking things into manageable chunks helps us to accomplish goals, so maybe a timeframe less than one year would be more appropriate.
There really is a thin line between a goal that pushes your limits as intended and one that restricts you to doing less than you are capable of doing. My marathoning goal is mostly a matter of convenience. There are marathons all over the place now, but otherwise there's no good reason to stop at 26 miles. Why not 30? Why not 40? The 26-mile mark is set as the "finish line," but if I set the finish line at 30 miles I could probably make it. The weariness I'll feel as I approach 26 miles probably wouldn't be as bad if I was thinking in terms of going for another 4 miles. If I set the mark at 30, I may not feel the same level of exhaustion until mile 29. Obviously there are limits to this, but it's sometimes difficult to tell when the limits are psychological and self-imposed, and when you've really gone as far as you can go.
At this point you may have set an immediate goal of preventing yourself from gouging your eyes out as an involuntary reaction to this annoying flood of speculation and self-questioning. Let me assist you in achieving that goal by moving on to some less drivel-rich content...