Most programmers use laziness all over the place, they unfortunately have few tools for introducing it, and thus don't recognize it as such.

For example in C/C++ your only ability to introduce laziness is via manual thunking, if, or the logical conjunctive (&&), and disjunction (||) which have non-strict semantics. For example you often see the idiom of:

    if (x != NULL && x.foo == bar) { ... }

Which relies on (&&) being lazy in its second argument. Lazy languages allow one to write things like && and if without needing them baked in. For example:

    until :: Bool -> a -> a -> a
    until b t f = case (not b)
      True -> t
      False -> f