How we cite our quotes:
[Case'd] been numb a long time, years. All his nights down Ninsei, his nights with Linda, numb in bed and numb at the cold sweating center of every drug deal. But now he'd found this warm thing, this chip of murder. (12.7)
We see Case's numbness as a part of his self-chosen isolation. Here we see the barriers of that isolation begin to break down through anger. Interestingly enough, it wasn't getting back into cyberspace that did it, but the anger Case feels toward Wintermute for how he treated Linda Lee and Molly.
"Of course I dreamed. The cold let the outside in, that was it. The outside. All the night I built this to hide us from. Just a drop, at first, one grain of night seeping in, drawn by the cold." (15.79)
The Tessier-Ashpool family use cryogenic tubes to isolate themselves from time and the outside world, so they can extend their family's influence through the decades. This sounds great, in theory, but think of all the things you'd miss. New lolcats, the Oscar award ceremony, Superbowl commercials, you know, the important things in life.
"I like it, you know? Like I've always talked to myself, in my head, when I've been in tight spots. Pretend I got some friend, somebody I can trust, and I'll tell 'em what I really think, what I feel like, and then I'll pretend they're telling me what they think about that, and I'll just go along that way. Having you in is kinda like that." (16.23)
Through the simstim, Case and Molly can connect to each other despite being in two different places. It helps Molly feel less isolated during a difficult time. Although today we call this technology an iPhone, in 1984, it was pretty amazing to think about.