If you have a long term goal, a big goal, or anything that at first thought is maybe out of your reach, you have to break it up into smaller pieces. I say this thinking on the long process of training and exercise that brings me to Mt. Everest. June 2006 when I hiked Longs Peak solo without sleeping all night. I didn't need to do it. It wasn't very challenging. It was really just an eight hour hike. Yet I was so tired on the way down and on the drive down to Boulder, I almost drove off the road.
That is one specific example about how I did something physical while pushing through tiredness and when I am late coming down from my summit day in Nepal, and the sun goes down, it won't be one of the first times I have had to descend while extraordinarily tired.
I'm being more specific than I want to. The point is, if you want to go after something big you have to break it up. There are the technical aspects. There is often a physical component. There is the social, mental and emotional aspect. There is the financial cost. There is most certainly a timeline. Within those broad categories there are sub categories. On Everest, from a technical aspect, there are mostly snow and ice sections, but there are also rock sections too. To race a marathon, it helps to know you can run 27 miles, and know that you can run much faster than marathon pace at least for a short time. To become CEO of the company, well you have to get there before you retire.
If the goal is big, challenging, all of the things a good goal is, is must be broken into smaller pieces.