It may be the fear of failure that keeps people from ever bettering themselves. Do not ever be afraid to fail, be afraid to never start your journey.
Knowing where you want to be... Setting a goal...
This may be one of the most overlooked tools in a person's arsenal. If one does not set goals, then they are running blindly and cannot plan their life accordingly [whether it is for fitness or life in general]. There must be an end game in mind.
Even more overlooked is the little achievements along the way... Setting an overall goal is great (to lose weight, to build muscle, to make more money, to be more attractive...) but you also want to set specific, achievable goals to keep you motivated along the way.
This is a diagram that each of my clients know very well.
Start by writing down where you are now. Be honest... but not brutal.
After that write 2-3 easily obtainable goals for the next month. These must be specific (lose 5 lbs, write a resume, etc...).
After that, write 2-3 more slightly more general goal for a 3 month goal. Continue being more general for 6 and 12 month goals.
This will be your map to success. Now you can plan your workouts, your career, your life accordingly.