Is there really a place on your neck that if someone hit it real hard and fast you can die?

Yes.: Execution and suicide by hanging or abrupt hyperextension of the neck eg. In a car accident or blow to the chin are all classically associated with a displaced fracture of c2. In hanging, if no fracture occurs, death is typically by asphyxiation. Carotid massage can lower blood pressure and heart rate, which theoretically may lead to death in someone who already has cardiac or stroke issues.

Mostly in fiction: Dr. Ayres is right. Assassins fast-kill by dislocating the upper cervical vertebrae. The idea that touching the carotid sinus (the pulse just below the angle of the jaw) can cause sudden death (instead of just slowing the heart, which it unquestionably does) is a common defense by lawyers representing stranglers -- if it ever happens, it is very, very rare.