The buddhists say something like “watch your thoughts because thoughts become actions”.

Could be some part of you is using “other people can tell what I’m thinking” to represent the reality that “the world will judge* me based on [what I do]*”

Where these terms can be expanded to:

• “judge” = provide feedback in terms of situations that develop around me, which are either pleasant or unpleasant for me
• “what I do” = The overall set of “karma”, ie mental patterns that consistently manifest in behavioral patterns

So even if individuals around you can’t hear each of your individual thoughts, your mind uses that scenario to represent the reality that the contents of your head will come out, and the world of people will respond when it does.

This is probably why we have such a tendency to believe in “God”, which is an omniscient person. Just like the hippocampus which evolved for navigating physical environments also serves as a planning center for navigating abstract landscapes of possibility, it could be whatever mechanisms evolved to handle other individuals who will modulate their relationship to us based on how we treat them, to also model the way that certain behaviors will eventually lead to certain types of response from physical reality and the social world.