Somewhat inspired by this question: For what common problems is functional programming not a good fit? - but nevertheless a question which I always wanted, but was too afraid to ask.
I've been in ... well, let's call it engineering software development practically all my life, and in all that time, although OO had always been there (well, most of that time) I've never had the need to use "its ways", nor to learn that paradigm. We've always used rather simple program structures, routines/functions/modules and although it is opposite to today's best practices managing those programs (programs up to roughly 300k LOC, nothing too big) never proved to be difficult, let alone impossible.
So I wanted to ask you, what would be the sorta problems for which object oriented paradigm would not be a good choice? In comparison to procedural programming ?