Why is it important to be friends with people you work with?

@Topic,
I don't think friendship is important, with your co-workers. May even be a pain in the neck.
Better to get on well with everyone without the added burden of friendship.

show me your friend and i will tell you who you are

as a geek, i have nothing in common with 90% of my colleagues at work. end of story.

In Nigeria , i think we use the word 'friend' loosely . we have colleagues, neighbours, acquaintances , brother/sister in the church etc. everyone doesn't have to be a friend. U dont have to be friends, just get on nicely with everyone, be pleasant, co-operative etc identifying those with whom you need to have a good relationship to succeed job/career wise. At the end of the day, its no joy being unpleasant and having bad vibes cos lets face it the bulk of your day(s) are spent with colleagues and it can be a bit unsettling to be at close quarters with someone you have issues with. So be friendly not necessarily friends