Over the last year, I have very likely set more goals and failed to accomplish more of the goals that I have set than most of the people that I know! 

For example: In regards to the amount of times I've wanted to post to this blog...I've failed. In regards to the amount of miles I've wanted to run...I've failed. In regards to the time I wanted to finish the SF Marathon in...I've failed

So why do I even set goals every month and every year, if I fall short of them more often than not?

I continue to set goals in spite of my inability to consistently achieve them, because the funny thing about goal-setting is this:

I achieve exponentially more by setting and falling short of a goal than if I were to never set a goal at all. 

Though I endeavored to write 5 times a week (over this last year) and only wrote 2 times a week, I know I wouldn't have even wrote twice if I wasn't aiming for 5 times!

Though I endeavored to run 100 miles a month (over the last four months) and only ran 88 miles a month, I know I wouldn't have even run 88 if I wasn't striving for 100 miles!

Though I endeavored to run the SF Marathon in under 5 hours (my previous PR was 5:54) and ended up running it in 5 hours and 17 minutes, I know I wouldn't have beat my previous PR by 37 minutes if I wasn't attempting to run it in 5 hours!      

In other words: I'd rather set a goal and achieve it partially than not set a goal at all! Some achievement is better than no achievement!

Quit perfect.

Set a goal and pursue it. If you achieve it in its' entirety, great. If you don't, you will very likely achieve more than you would have if you never set it in the first place.