Wolpert explains that his group tried to reverse engineer how humans control movement. What makes this difficult, and what is the example he uses to demonstrate the concept?

You are travelling on a long non-stop flight from tahiti to tampa. you have been in the air for about 7 hours and have not moved, since you boarded the plane at tahiti. you need to use the rest room and on standing up feel dizzy. the best explanation for your dizziness