Courage is one thing, but overdosing is not a pleasant experience, even if it is usually not (physically) unsafe. Cannabis edibles are famous for this since most people have no idea how strong their brownies even after they make them. It was one of the main reasons I made an online calculator as a side project (http://www.scientificedibles.com) to help people to estimate dosage, rather than "take one" and end up on the floor.