I wouldn't say that, but people have a rather... Lax sense of what insanity is. It's not like it's an on/off switch. It's just a thing that, sometimes, offends due to being different, while others it doesn't because it's usual. Like racism. Horrible and unacceptable to others, but the way of life to an equal amount. Generally, when making an "insane" person, just create them with a certain mindset and personality that you would normally find repulsive in real life, and let others decide if you're insane or not. It helps if you happen to enjoy the personality you know that under normal circumstance is unacceptable. Like being a Omnicidal Maniac or Pedophile. It's not like you have any legitimate reason to be a mass murder or would want sexual relationship with children, but to [i]create and become[/i] the character who thinks they can and should, and you'd be taking the right step towards being an insane person. Typically when the cops have wrestled you to the ground.