It's clearly how meaningful is that word. You can success or fail because of that word. How much do you understand and hold to it can cause so much in your life. But, not everyone can understand it, use it, and hold to it forever.
I personally feels that especially every guy must be friend with it. Not just guy but woman as well. A man without any discipline can't lead others. My dad is a man with discipline and principles. Yes is yes, no is no. That's why I salute him. I wish my dream guy will also have this character :) *giggles*
I must have DISCIPLINE. Now, I must be discipline in my studies. Studies is my first priority. Nothing else matters. Is it? ;)