When you know what you want, isn't it much easier to get it?

I would say that it is, at best, an over-simplification, COL Mikel J. Burroughs.

Sometimes the only way to succeed in satisfying a need is through a process of incremental discovery, definition, and accomplishment. Just knowing the desired end goal does not guarantee that you will even have a clue as to how to get there from here, much less the ability to do so.

Goal setting, defined plans, pathways. It is hard to get anywhere when you don't know where you are going our how you are going to get there. When I was cadre at the Arizona Project Challenge that was a large piece of helping the kids. What do you want out of life? How can you get it? What must you do to make that happen? What are the obstacles between you and your goal? How can you overcome those obstacles? Too many times we just play the bull in the China shop role and think that should work. It normally doesn't.

Improvise, adapt and overcome. And if it turns out to be unattainable, accept it and move on.