Part of what keeps me going is setting (and then trying to reach) goals. So I figured I'd write about how I do this to share how I go about the process (haphazardly, actually). Then I figured that more common advice - with the added benefit of not having to write it on my own - could be found here. Click that link for all sorts of posts on the topic of goal setting.
As an aside, the way I set goals isn't by any means mentioned in those series of posts. I sort of just say, "wouldn't it be cool if...?" then think "now is this feasible...?" and then set whatever it is as a goal. If this doesn't make sense, it's probably because my method is, well, not really a method. And if you have difficulty keeping track of things, or prefer methods, then I don't recommend my approach to goal setting.
I also wonder how important it is to be flexible with your goals. On the whole, I think being flexible about your goals is more important than having the "right" goals. I know I didn't set starting a company as a specific goal - and then, lo and behold, the whole thing sort of took off on its own. The same goes with reading - I never set out to read a certain amount this year, but after being challenged by a former boss to read even more I decided I could (and would enjoy) reading 2, 3 books per week.
The other thing that got me thinking is people who don't set goals. This isn't necessarily bad, but I wonder how many successful people have gotten to where they are without setting goals. Perhaps those people were the beneficiaries of luck? Nassem Nicholas Taleb would certainly think so.