I've been doing quite a lot of interviews of candidates for several development and QA positions, and I'm constantly amazed how some people don't write the truth about their knowledge and experience.
It might be that people think that they are more knowledgeable than they actually are.
I don't know.
I met people who claim to be proficient in algorithms, but cannot describe a sorting algorithm. I met people who claim to be proficient in some programming language, but as soon as you present a simple task to be performed in that programming language it turns out that they actually were only participating in a course where that language was used and don't have any real understanding or proficient of it.
What do these people think? Do they really think that their lies will not be exposed? Even if they fool me and others in the interview, don't they think what will happen when they actually start working and be expected to perform?!