As for the suggestions -
Get a social life - For one, I'm not too keen to do that. Going to a bar is not really an option. I don't quite link to have a drink just for the heck of it. And beyond a certain age, I really don't feel like socializing as I used to do while younger.
Have a hobby - Well, most of my hobbies are not social hobbies. I enjoy software and tinkering around with hardware, but that's about it. I do like going for rides, hikes and treks but that's because I enjoy the solitude.
I think there is a particular aspect of social interaction that gets fulfilled at work. Talking about some small things, not for too long. Meeting people face to face whom you've enjoyed working with. Sharing work related anecdotes. These have a special place which don't quite get fulfilled elsewhere. And all the while having a clear line which doesn't get crossed is a relief and one which we take for granted.