Lazy lists, anyway. As far as I know there's no built-in support for lazy scalar evaluation.
What does Perl 6 not have?
Users.
Hmm, I figure it's more the the optimizer depends on code not exhibiting undefined behavior, like in C. It's not really the case that it's lazily evaluated, just the the causality gets screwy when you try to observe things in an asynchronous system without any kind of coherent memory model.
The fastest anything can travel is the speed of light, which is the speed perceived when a result is already calculated and held in a CPU cache. For everything else, it must be loaded from RAM, Disk, Network and perhaps also operated upon - which can never be as fast as the speed of light.
Reality wouldn't type check.
Reality lacks a compile stage entirely - hence all the runtime errors.