Why do people who are sociopaths have like this bright shiny demeanor and people who are actually nice have this not so bright depressiveone?

Answer 1

I have heard that one sign of the sociopath is their habit of constantly agreeing with you, which tends to win your approval. If you hate something, it's "Me too - that's the worst !" and if you like something it's "Wow ! Me too ! I can't get enough of that !"

If we consider that the sociopath is always putting on an act about what he thinks, it's not much of a stretch to suggest that these people always put on an act about how they're feeling.

Answer 2

Sociopaths are very good at manipulating people in making you believe they are a certain person. They will purposely shift they act to fit what makes you believe is a bright and charming character. Actual nice people know the reality of their gift of niceness being used against them. The nicest people are most likely the most broken. They don't really get giving back what they give. Sociopaths can just take what they want.