I kind of stumbled upon this while I was trying to tap my foot to the rhythm while playing. I realized that if I try to tap my foot on every beat in time, my timing goes to shit. But if I don't think about it and let my head bob, or my foot move whenever it feels like it (still in time, but maybe not every beat) then my timing is great.

This made me notice that whenever I'm playing guitar if I try and do anything at the same time, my guitar playing will be useless. I can't talk while playing guitar, even if it's something simple like a yes or no. I definitely can't sing at the same time, and sometimes, just my girlfriend walking into the room can throw me enough to mess up.

At the same time though I don't feel like I'm really concentrating hard on playing when I'm... well... playing. It's more like being zoned out and just listening to what I'm doing. But I lose my spaced outness if I have to actively think about anything.

Is this normal? Does anyone else have this problem? Is there a way to play and talk at the same time? I mean, obviously there is, but music I can play flawlessly will hopelessly fall to shit if I have to say hi to someone.
It is normal, you'll gain the ability to do whatever while playing guitar in time.

also, pics of girlfriend are needed
That's why I don't have friends

Think of it this way. When you first started driving, or if you are young, how about riding a bike... were you able to juggle while eating an ice cream cone while talking on the phone at the same time?

Well, chances are you still can't do that now, but my point is that the more familiar you become with something the more you'll be able to divide your concentration. Singing while playing, especially while playing different rhythms than the rhythms of your vocals, takes getting used to as well. As does syncing your hands together when you first start playing piano, or pressing Up-Up-Down-Down-Left-Right-Left-Right-A-B-Select-Start on a SNES controller to activate the 30 lives cheat in Contra.
I have this to a degree, I can move my head and foot to a rhythm consciously but mostly do this unconsciously. I can talk depending on what I'm playing/saying, like sometimes I have to wait for a particular point in a riff before I can blurt something out quickly.
Speed is a by-product of shut the fuck up.
I can usually talk in short sentences when I'm playing, but other than that, yeah I pretty much have the same problem.
I've been having the same problem and it recently started bugging me because i saw a video of myself playing and i looked so rigid. As a warmup try practicing on being as relaxed as possible and you'll start to feel alot more comfortable. this alone did wonders for being able to move around while i'm playing.