I am a rather introverted person. Which doesn't necessarily cancel out the fact that I am kind of an extrovert. For instance, when I am in a group situation and I have to "schmooze" I can do so with expertise. People have told me that I am warm and engaging, which is nice, but it's not really who I am. I need recovery time afterwards. (Not that I'm not warm and engaging, I just prefer to shed my warmth in a smaller setting!)
I love cyber friends for that very reason, especially writing cyber friends. You carry on a conversation on your own time. The other person understands if you don't talk nonstop because you can actually get up and leave the conversation for a bit and no one is offended. You can get involved in what you are doing and not bother with them. When real friends come over you can't do that. You have to give them your full attention. They stay for far longer than you would like and take up far too much focus. If they were online you might have just exited them and gotten back onto the task at hand. Or you might have gone stealth to get some work done without interruptions.
But sometimes writing does get lonely. Right now I want to talk plot with someone. My great idea has grown wings and I need, need to talk it over with someone who knows what I am talking about. I love my family and friends, but most don't have a clue. Can't instantly grasp the possibilities, don't understand all the implications of changing POV or setting. Where oh where are your cyber friends when you need to chat?
Of course, they may have all gone stealth at the same time!