Visualizing the Entire Path

Let's say you have a goal in life, but you don't know what steps will be required to get there. The only step you are sure you can accomplish is the very first one. Maybe that first step involves quitting your job, or moving, or doing something else that is hard to reverse.

Do you take the first step and hope you can figure out the rest later? Or do you try to figure out all of the steps, at least in a general way, before you take the first step?

Every situation is different, so generalizing is r