Do you have a power or stamina? And how to improve yourself in order to solve this equation?

i blive that every one have both but in levels  and sales man if he is good one must look for self   improvement evry day  suach as find out way he feal to finsh this sales matter  what is his missteac did he boush so much or did not get right time  some times  he must get penfits of some one experience  or watch  and leasin to experience sales man  - i can say that all men should  carry all they power to success  or they must stay hoome