That's another perspective. But even if you don't get what you want, in my experience, you waste less time when you know what you want, because you just look for it, as opposed to looking for anything for a long time and then finding nothing.
I too often leave the store without buying, I'd rather leave empty-handed than with something I don't want.
Maybe it's not about goals specifically, but it is about having a clear direction. Although I admit it's really great when you find that thing you want and weren't looking for. But you can't plan for it.
And chance is always there, whether you plan for it or not.
I remember when we were children, roaming around the empty fairground looking for lost money. I never found a note because I was looking for it. But if I didn't look, I found money somewhere else.
Yeah, that happens. :) But then again, one spends more days not looking than looking, so it's likely.