It's Your Choice
This is something that you must have an answer to from the beginning. You don't need to know why exactly, but you must have a goal in mind at all times.
As you make progress, it's easy to get sidetracked and lose focus. This is why you must ALWAYS have a goal in mind. By becoming a successful guitarist, you will not be simply learning to play an instrument; you will be opening a door to a specific way of life.