You can definitely get in a mode where you need to pull yourself out of the house, but I never get lonely.. Mostly because I communicate with my coworkers constantly. Probably more than I have at most brick-and-mortar operations. We idle in a Skype chatroom all day long, and I participate in at least a half dozen skype calls a day.. sometimes ones that become just two hour co-coding sessions.

The real need to get out is just a need to spend some time in the sunshine, or walking.. funny little things that happen on accident when you're commuting :)