Everyone has been created with the maximum capacity to do something. When this capacity is attained, one gets it hard to do more. But wait; there is always energy preserved to go an extra mile. Take for an instance a cleaner; when sweeping they do it very nicely, to the point of saturation when it is impossible to do more. However, when an unexpected dust clogs the well swept floor, the person will clean up the surface again, sometimes a midst grumbling and internal murmur. Nevertheless, it means that there is still energy to go an extra mile.
Going an extra mile means stretching a little further. This may bring the person closer to breaking point but he/she won't break. Everything you do today needs you to go just an extra mile. It may mean just waking up an hour earlier, adding a fruit to your meals, scrubbing the wall with a little more strength, raise your voice a little louder, step on that break or accelerator, or pedal a little more. If you are studying, your success might be lying in taking an extra hour awake or waking up earlier before the stipulated time. Anyone who goes an extra mile is always ahead. When others are struggling to catch up with time, he will be moving with time. This makes it easier to make necessary adjustments with little or no struggle.