I think it is a bad idea to trust others.
This topic has come up for me a few times this week.
I think it is a bad idea to trust others, because it is impossible to ever truly know their intentions or what they are up to. Obviously the only person I can know for certain is myself.
When people stupidly put themselves in situations where they were taken advantage of, it was also their fault for letting their guard down. I don't make exceptions for myself either and realize if I let my guard down and people lie and steal, it becomes my fault as well.
People seem to get offended by this and I don't understand why, because it only makes someone more suspicious if they get angry.