That's true. Do you know who else won a Turing Award? Tony Hoare.

What is Tony famous for? Well, lots of things, including his very important comparison sort algorithm Quicksort, but, in this context how about the Billion Dollar Mistake ? That's a pretty nasty booboo in many programming languages for which Tony blames himself because it was his idea.

Like your parent said, TeX shipped a long time ago and we learned a lot since then, it is not a surprise that we know how to do better today, in fact it would be a serious black mark for Computer Science if we couldn't.

Which means what, exactly.