People are busy, people are tired. They do not want to sit through and deal with things that are important to you but not to them.
Negatives are turn-offs.
Listen first before offering advice and solutions that are not possible. There is not much point in explaining to someone how to bake a meal in the oven when he or she may be using nothing more than an electric skillet because there is no working oven available. Teach one or two concepts, not ten all at one time. People aren't stupid, but they may be unfamiliar with the material you are presenting. It is important to build their trust and rapport and help them increase their comfort level.