Minimalists argue over the use of goal setting. For some it is superfluous, even obstructive. Others think great deal of it as a form of visualizing one's desires and influencing the subconscious. To me it is just a tool to bring awareness to what I am heading for. In some cases it works brilliantly, but sometimes it doesn't help at all.
It is important to understand that some activities just do not have a purpose. When children do role plays, they don't try to achieve something (although it is of great value for their psychological development). But then again, games like chess don't make sense without a target and definite rules. Applying this to personal goals we can distinguish two categories: present-oriented and future-oriented. Meditation is a perfect example for something that only happens in the present moment on the one hand. It may have long term benefits, but doing it for that reason means to miss the point. On the other hand consider writing a book. It is enjoyable while doing it, but kind of dissatisfying when not brought to an end. In my experience setting goals works best for the latter.
Funny enough, here are two examples where it is just the other way round:
I do sports merely because I love it. The sensation of my blood rushing through every cell of my body makes me feel alive. Of course I know of the health benefits, but the reason why I train is just that I enjoy it so much. Consequently I used to never set specific goals. My objective was to get stronger, but not by numbers within a certain amount of time. In general that worked fine, but for deadlifting I did not make any progress. Only when I decided to aim towards a definite weight, I found out that I had been afraid of injury. I never really gave 100%. After having set my goal I began to improve rapidly. So in this case having a goal helped me to become conscious about why I got stuck.
With songwriting I had once set the goal to add a new part to the song I was currently working on every day until it was finished. After a while I felt like running out of ideas. Retrospectively I ignored the principle of input and output. Only when I stepped back from my original goal, creativity returned and I was able to finish the song.