How To Fix (Not Achieve) Goals?

My problem is not that I can't achieve my target. My problem is to decide which target to hit! How do you prioritize and reduce your goals to a focused few? Let's say you have 20 equally excellent food. You can't eat all of those - no way. And it's very difficult to find which 3 are most tasty amongst all these without tasting each of those 20. Do you taste all 20 a little bit then? In that case you won't actually eat any of the food properly. Or do you deliberately decide here are 3 out of those 20 that I am going to eat? Which 3 then? Randomly? How do you decide? I have read plenty of books, countless pages to find the answer - its not written anywhere. Everyone says once you fix your goal, how to achieve it. Well that's easy. No one says how to fix your goal in the first place (actually some people do say but that doesn't answer my thirst). Having options is a bless most of times, but for me sometimes, having options is the real pain! Any help?