~ Carl Sagan ~
We are all endowed with our own set of genetic attributes. Then those attributes are molded and refined through our youth like the clay in a pot to form the special person we are. Unlike a pot though, we are never finished, glazed or fired to hardness. We are in a perpetual state of building, polishing, wearing down, breaking and reforming. All of this process and our success or demise is dictated by our attitude and effort. We can allow things to happen to us or we can create what we want through the strength of our body and mind.
Every part of us is in a constant process of change whether we are 11 or 111. Our task is to make the most of what we have either through exercise, thought, preparation or neglect. It is important to use our strengths to compensate for our weaknesses. It is also important not to give in to our weakness because doing so also takes part of our strength. Not being able to run a fast 10k should not keep you from taking extra steps to make you stronger. Do what you can do with the thought of improvement rather than surrender. Only you know what you tell yourself. Life is not easy. If you pretend it is, you will not get what you want, but will have to be satisfied with what is in easy reach.
Each time you stretch for a goal you are exercising your body, spirit and mind, preparing it for the next stretch. Each time you can reach a little farther. As Carl Sagan wrote above; you need to exercise your brain as well as your muscles. You develop problem solving skills by taking on problems. You develop knowledge by feeding yourself information. You develop character by exercising proper judgement and learning when your judgement is off.
Try not to develop a single part of your being to the detriment of others. What good does it do you to have the best body if you have poor judgement or morals? What good is it to know everything if you give up a functional body. The best You has to include all of you.