Fred likes it in her room. She's got her magic markers to write with and the smooth plaster to write on - much easier than chalk and cave walls - so she can get down any formulas or ideas that come out of the noise and clutter in her head. She doesn't need them to get home now, but she still feels more secure when her thoughts are made tangible. If they're real, then it proves that she's real, and she really did make it back home from Pylea, and she doesn't have to be scared all the time. Doesn't have to be, although she is.
Sometimes she'll open the door and walk outside, but even the corridors stretch on and on so dauntingly. Then she thinks about how they'll eventually lead to a big open space like the lobby or outside, and that always sends her scurrying back to her room, all nice and small.
Some people have claustrophobia and get agitated or scared in enclosed spaces, or develop cabin fever - a term Fred finds kind of misleading, since it doesn't apply only to cabins and the afflicted don't develop fevers - if they stay in them for too long, but she loves them. In Pylea, any monster going for an afternoon stroll might have spotted and killed her on the plains, while in the cave she was hidden away. She was safe, relatively speaking. Cordelia assured her that Los Angeles is nothing like that, and at least she wouldn't have to be a fugitive because slavery was outlawed in 1850. But then, apparently there are monsters and magic all over California too, so Fred thinks it's closer to Pylea than Cordelia believes... Although in Los Angeles the food tastes better, mostly, and the humans don't know about the danger they're in. She likes that. It sounds so comforting. Fred herself is perfectly aware that vampires - the nasty ones, not the heroic, souled ones; she doesn't want to discriminate - roam the streets at night, looking for vulnerable, isolated people to feed on. Not to mention the portals, which could open in any place at any time... It makes her nervous. Better to stay in a single place and lower her chances of getting sucked in.
The other obstacle is, everything will change when she leaves her room for real. The world is so huge and full of everything, and there's no telling what's going to happen next or what manner of things are lurking just out of sight. Before the TV got to be too worrying and went to live in the closet, she would watch it sometimes. The people on-screen handled all these things she hasn't seen for so long, like clubs, malfunctioning robots, broken hearts, alcohol, mobile phones, rare diseases, dogs, sex in inappropriate places, cars, murder mysteries, aliens... Some of those things she's never encountered personally, but they were concepts she'd all but forgotten, and to see all of them at once is disquieting. She likes being back and having access to certain things, like tacos and a cosy bed. But even before she factors in the demons and portals that might gobble her up, going back to a normal life so suddenly and having to deal with all these normal things from TV at once is a much more challenging idea than she's able to deal with for the moment. So she won't.
That's without factoring in the people themselves, even Cordelia, Wesley and Gunn, who keep trying to talk to her when they bring food up. Perhaps feeling intimidated by them is rude, and she doesn't want to be ungrateful, not when they've been so generous to her. They are nice and she likes them, but for five years, two months and thirteen days, other, human people - even the nice ones - weren't something she had to worry over. It was just stay alive, don't get caught, keep your head attached to your body, and try to find a way back home. She was always a little awkward anyway, but it used to be merely a manageable quirk. Now, she doesn't know how she should interact with people at all. There are rules; patterns to conversation, and things she should or shouldn't say, and social cues to pick up on, but she can't remember them and as much as she's tried, she can't figure them out. It makes talking very problematic. She can't even imagine handling all the social interaction that the others must have every day, although she suspects it would quickly lead to her brain's dissolution. Better to stay out of the way of the others, with her brain still intact in her head.
She wishes Angel would come back. He'd be too busy saving folk and contemplating his eternal existence to be able to spend much time on her, but he might be able to visit occasionally. And he's very reassuring when he's not a vicious green monster – well, technically he's always a monster, but a good and heroic monster, not a proper one. So she's not at all concerned about him trying to eat her or chop her head off. Rather, he's so kind, and she never caught him looking at her funny, or talking to her in that "I'm being nice, but what you just said was nuts," tone she's getting uncomfortably familiar with. Not that the implication behind the tone is inaccurate... She can't always make sense of her mind, it isn't fair to expect the others to.
Still, Fred's hoping she'll be better when Angel returns - if Angel returns. She thinks she could talk to him okay, and he could tell her more about the world beyond her room. When she'd been around him, she'd started to feel more like someone else, from a long time ago. A girl who was brave and safe and sane, who knew how to walk in the world and make small talk like a person and had a bright future ahead of her. It would be nice, to feel that way again. At least for a little while.