Writing can be a solitary profession. Writers are, in fact, often notorious for their lack of social skills. Harlan Ellison comes to mind.
People outside the industry have even more of an image of the writer as somebody who sits at a desk for a few hours a day and doesn't interact with anyone.
It's not entirely accurate. True, I do spend my work day at a desk in my home, but during the course of the day I may interact with editors, artists, collaborators, writing buddies, clients...
It's actually very important that a writer learns to play well with others (especially if you have any inclination at all towards writing scripts). We have to be able to deal with all kinds of different personalities. In the past, agents handled a lot of it for us, but agents (and advances) are like meals on airplane flights - you only get them in first class.
For me, working with others has always been the hardest part of writing. I'm shy and a little socially awkward. I hate talking to strangers on the phone. Heck, I had an anxiety dream about Balticon last night - I dreamt I was wandering all through the con and could not find the panel I was supposed to be on. I used to get terrible stage fright, but managed to get rid of it. I still get the pre-jitters, though. I've been found crying in restrooms twice before "going on" to do something. I like interacting with people. I just find it hard. I think that's not atypical for writers...I think that creative and storytelling types who thrive on being on stage and under a spotlight don't write. They act.
Learning to treat everyone well, learning to face a crowd - these things are actually important, but again, often neglected by writers. (I'm told Toastmasters can be very helpful if the idea of giving a reading makes you want to go find the nearest hole in the ground). It's especially important for spec fic writers who have to do con stuff.
Oh, and get good moral support. Your spouse/partner, a friend, heck, if you can get away with it, your dog...