Lambda the Ultimate

I've heard a lot that writing a function in lisp will yield a function equivalent to any of the built in operators, therefore it is entirely possible to re-create any of the built in operators using lisp code. However, this can't be done in C because of its syntax rules. But if C did use prefix notation then I don't see a reason why you couldn't re-create any of the built in operators using C code. So basically what I am wondering is if it is prefix notation alone that makes this claim true in lisp or is there something deeper going on here that I am not seeing clearly?