I do socialize with my co-workers, but only secondarily. Time with them is time away from my family, and I greatly prefer the latter.

Slightly off topic, but all this talk assumes the person has good relationship with their immediate family, and/or is having a successful romantic relationship. Something that I, as a fresh graduate single dude who's not on great terms with family, would argue is also a privileged position. You really shouldn't judge what people choose to enjoy in their lives without knowing their circumstances.

Yes, this is all true and good to keep in mind. Thank you for raising that point.