"No citizen has the right to be an amateur in terms of physical training. What a misfortune it is for man to grow old without ever seeing the beauty and strength of which his body is capable. "(Socrates)
He considered that all effort and dedication is rewarded. One day they told me that I could not make a change in myself, but today I show the opposite. I've been practicing gym for about a year. It has become one of my best habits and it feels good to be healthy and full of energy.
Yes someday they say "You can not" are talking about their limits, NOT YOURS!