"You need some form of dynamic allocation construct (malloc ornew or cons will do) and either recursive functions or some other way of writing an infinite loop. If you have those and can do anything at all interesting, you're almost certainly Turing-complete." -- http://stackoverflow.com/a/449170
Have you seen what sleep deprivation does to people? Have you seen how it causes people to lose their impulse control and go crazy ? What about driving ?