What do i say about people who do not carry a pen on their person while at work?

I thought it was a given until i realised to the contrary, and rather irritatingly at that, when i failed to get one from any of my colleagues nearby, when ran out of ink. I find it thought provoking, that people do not find having a pen very useful, because they sure do remember to carry their combs,cigarettes, gutkas and whatever things. Is it coz, its more convenient to borrow one when needed? Or is it coz it will be borrowed if u keep one? beats me!