Yes, I borrowed the title form a famous joelonsoftware post for my question because I didn't exactly know how to ask this.
I'm a professional programmer for a few years now and although I followed informatics courses in school there was a lot of stuff missing from the curriculum, as I now know but wasn't aware then. For example I didn't do any compiler theory, algorithm analysis (the Big-O), have no idea what P-NP meant etc.
So I want to catch up now!
But the field of computer science is big. Really big! So from here my question: What's the absolute minimum every software developer absolutely, positively must know about computer science (no excuses!)?