A couple days ago I realized that programming is by far the most social thing I do. Sure, I discuss things with other developers, QA, and business analysts, but that's a small part of my time. The vast majority of my time is spent looking at what is already there and trying to understand it. Not just what it does or how it does it, but why. And this requires a Theory Of Mind.
A theory of mind is when you realize that other people have their own mind and their own ideas that are separate and different from yours. Everything I see at work isn't some naturally occurring thing - it was created by someone, it has an intended purpose, a reason for being, some business or technical need that it meets. Much of my time is spent interacting with others but only when programming do I need to look into so many other minds at the same time, to find and understand the intent of the original developer, the business scenario being addressed, the reasons why it was done this way and not that way, and why it's still being done this way. Writing code generally isn't difficult, especially business apps, it's understanding the intent and reasons for the code that's tough. Like it says in Structure and Interpretation of Computer Programs, "Programs should be written for people to read, and only incidentally for machines to execute."