In my experience they often lack the curiosity to find background information and possess an adequate overview. Like they'll be able to write quite decent code in C++, but in an interview they'll fail at an easy question like 'what are the differences between C, C++, and C#.' (like they'll have no idea about different paradigms)

It's a complacent sort of attitude, like 'I did a degree, so obviously they taught me everything worth knowing.'