Do people actually have a hard time believing that people are capable of lying?

A lot of people in my area like...don't think it's possible for people to lie. Like they aren't skeptical at all, and I think it's a bad thing. I'm going to be straightforward with you and just stereotype for a second, because this stereotype is TRUE. In an affluent area, like where I live, PEOPLE ARE TOO SHELTERED TO THINK THE WORLD IS MORE THAN 10 PERCENT BAD! Why can't people just understand that people lie and cheat? Why is it hard for them?