What are the traits of a Good Ph.D student?

You give up well paying jobs to pursue something you like. You do want to do a Ph.D in Astrophysics, Math,Bio-chemistry or something similar.Then rest assured that (atleast the first couple of years)days will be filled with classes,arguments at the chalk/white boards, a quick lunch and optimism.Evenings start with more discussions and ofcourse end with worries about your grades.Nights carry with them HWs,restlessness ,late night pizzas and a "four-hour" nap on the office table.After all this you start with your research hoping to add your contribution to the sea of knowledge that keeps growing.A Ph.D is more or less a journey into the wild.You shall learn to be a survivor if you come out a better person than before.You spend nearly a twelfth of you life doing it.So learn to do it well.Came across this article which gives some worthy suggestions about being a good Ph.D student:
http://www.nature.com/naturejobs/2006/060511/full/nj7090-252b.html
Enjoy reading it!!