Self-discipline. Can It Be Taught?

This afternoon, when I was keying in at the computer desk some practice questions for the Q & A section of the GEPT intermediate level, a colleague sitting opposite me told me she had been wondering why some students, after 10 years of education, were still late for school. It seemed to her that quite a few students just waited to be disciplined.

I believe that self-discipline is an ultimate goal of education. But how can self-discipline be taught? Can this quality be taught or is it already in the blood when one was born? Looking back, I don't remember anyone in my life has explicitly taught me self-discipline, but I behave myself. Is it because of the books I read, the people I've met who set good examples? However, even surrounded by good books and good people, if I don't think, if I don't embrace and take in the goodness of all my experiences, I can be a different me now, or even a headache to others.