Meaning of life, did we know our mission?

As we been reach the half year of 2009, as now everything that I've been planned was done well. Come for my study, I can say that it's going smoothly. There so many things that we as a student/ college student should do in our life. From now on, give time more on study, forget/ less our time doing things through internet, chatting and as well as lazy going to lecture class.
What was the real thing or stuff that we do in our life? (as a student of cos) Did we really reach what we want to do? or did we use to listen our parents advice?
I'm becoming a future teacher, so there was so many thing running in my mind...can I make my future student an excellent or the worse persons...(oh no....that's my real mission someday)