What's your key of success?

Several days before, i was talking to my bro. She is the smartest girl i've ever met. She got 3.8 GPA in the medical faculty and 3.2 in the faculty of economy. She tell me something like this: "Hei, as long as we were talking, i've inspected any weakness on you". "You have a very good consept, but i'm affraid you are the one who destroy it by your self. And you don't have a valid purpose either". I was shocked because i thought it was a verygood critic. She tell me about the story of "Mahapatih Gajahmada". He was the greatest commander in the history of "Majapahit", an ancient kingdom that had ruled over Java and Indonesia. He was swearing that he would uniting all the country of Indonesia, by rising his a little sword less then 50 cm long called "Keris". She asked me "Do you know the meaning?" I said "no, tell me then". She tell me that Mahapatih Gajahmada wasn't meaning to rule all the country with all his ammo nor weapon. He just used one little keris. The lesson we can take about this story is, we must have a weapon to encounter this life challenge. Not many weapon but we have to master one of it, we have to make it as sharp as possible. In other words, we have to master one skill as good as possible, you have to be the greatest one who master it no mather how trivial that skill is because it will guide you towards the successful future. So what's your key of success now?