Question on motion sickness?

Motion sickness is generally experienced the first few times a person rides a car, plane, boat, roller coaster, camel, ect because the brain is not used to the sensations it brings. Many things such as a bad experience, anticipation, tiredness, or foods that unsettle your stomach also contribute to the cause of motion sickness. It is not known why some people are only affected by certain types or why some people do not seem to be affected at all.