Wouldn't a sociopath not know that's an unusual reaction to have though?

When the thought popped into my head I knew that's not what how people are supposed to react, and I didn't act on it. In fact I'd even done some free work for the guy at an earlier point, not bothering to chase after him for the pay he had promised me because it wasn't over much money, the work hadn't taken much effort, and I didn't want the awkward hassle.

I was just surprised at the how detached the thought was... there wasn't any attempt by my mind to sugarcoat it. It was as though we were playing chess and he'd just made his move, and now I was looking at the pieces to build my strategy.