It's true, you will achieve that which you give the greatest focus. I have a few first-hand athletic experiences to pass on regarding this exact thing.
Story 1: On my first off-road bike trip, I was following two more experienced riders on what can only be called a 4-wheel drive track. It was a dirt road in the "out back" of Thailand, intended for one lane of traffic. Due to the heavy annual rains this road had crevices within crevices, leaving 2 to 4 inch ledges to ride on for long stretches. After watching me pull myself and my bike out of the road for the third time within a quarter mile, my riding buddy called out "Only look where you want your wheels to go!"
Story 2: For my first international ranking kettlebell competition, I set the goal of Rank 1. With the advise of my coach I determine my goal rep count, then calculated 110% and programed "percentage set" workouts. Being a hard core type, I decided to make my goal higher than the rank requirements, preparing to make Rank 1 and possibly win my event!
About three weeks before the meet I accidentally arrived at the gym without my training journal. Rather than take a trip to look up the previous workout, I estimated a number that might be the 110% .... but might be more, and programed the entire week in a different notebook. I trained with that specific rep number, working hard to learn the rep per minute pace for the entire week.
The week before the meet, it was time to reduce my percentages, keep the rpm's at "race pace" and get more rest. I looked over my notes and found that, in fact I had been programming at 120% of my goal rep count. No wonder I was so tired!
At the competition I performed more than 120% of my goal rep count, easily making Rank 1 and winning the event.
The morals of the stories: First, when setting your goals, please please please, focus on what you want! You will get whatever you put your focus on.
Second, practice the way you want to perform. Replace one botched effort with six super-focused, correct repetitions. Learn more efficiency during the practice sessions, you will fall back on your training when the pressure is on. So train well!
Please feel free to leave comments or email me with your own success story in reaching a goal!