Swiss Re interview questions

I received a call from Recruiter and the interview was arranged. No proper communication about it The interviewer asked some oops questions which I have answered, then started lot of questions on multithreading which I answered as well then kept digging at all the concepts which are never heard of. I don't understand these kind of interviewers fetish where they ask some lame unnecessary concept nobody uses. they should ask how a person is able to think, if he can think he can solve any problem.

scenario based questions. clear answers to the queries. in depth knowledge of the interviewers. three rounds. 2 of them were technical. one with business. finally hr round for salary discussion.