Interesting that 3 out of the 4 can actually sometimes inhibit success.  If you believe in ability, there will be a task sometime where you feel you don't have the ability.  Other people are great until you are alone.  Luck works until it runs out.  Only effort constantly contributes to success.

I find this interesting because effort is largely downplayed in many of my social circles.  When someone fails, we joke about them receiving an "E for effort" instead of an A. 

So the next time you feel you are failing at a certain task, honestly ask yourself if you are giving it your best effort.  Don't try to make excuses or find others to blame, look only at yourself.  Chances are you can give it a little something extra. Like Rudy.