Since I've been married, I make no particular effort to maintain or establish friendships. The small social circle of my wife, her family, and my family is more than enough for me. And I have never been more satisfied with my social life, such as it is.

That's not to say there are no people I am on friendly terms with (coworkers, exes, ex-coworkers, people I knew 20+ years ago in college, etc).

From a utilitarian standpoint, it's important to have a few people you can reach out to to find work. And from a social standpoint, the times of my life where I had no social connections were difficult. But people have different needs, and my social needs are very modest. Do not feel bad because you don't have friends just because you think you're expected to.

As far as the title of the book, I believe eating alone is one of the great joys in life, especially when it's a respite from the forced social atmosphere of an open-plan office.