It may seem like a contradiction, but sometimes setting too specific of goals will bind you in and make achieving a target too difficult. Instead, setting a vague goal allows you the flexibility needed in order to achieve it.
For example, as a parent, finding time and energy to exercise is always tough. But in order for me to keep from gaining 10 pounds every year (I do love food & beer), I feel that exercise is important to my health.
I've tried setting goals like "run 3 times a week", but I never could stick with them. Some weeks I met it, but most were just too busy to hit the 3x mark. After a while, I'd gave up on the goal because I kept failing to reach it.
So last October, I changed my approach. Instead of setting a specific target, my goal was simply to run. Yes, I wanted to lose weight and get in better shape, but my focus was just to run. I knew that if I did, the chances of me losing weight increased and I'd probably end up being able to run farther than before. I also knew that if I didn't run one week, I could pick it right back up the next.
Now I'm able to run 4+ miles without dying. I haven't lost any weight and I've failed to run many, many times. It may have been an injury, a loss of free time, or simply a loss of motivation. It didn't matter though, because I stopped focusing on my past failures. I didn't care if I ran yesterday or not. I could run today.
I also stopped letting the possibility of future failures stop me. I quit worrying about not meeting my goal next week. I knew that if I ran today and failed tomorrow, that at least I ran once.
Sometimes you shouldn't invest too much in a goal. Just try it out. If it works, keep doing it. If not, no worries. Never assume you have to reach a specific goal for the journey to be worthwhile. There's value in every step you take.