I did not find any of the interview difficult - they had a set form with the typical questions such as
" what has been your proudest work related achievement" "what do you feel is you best attribute" "how would you handle a confrontational co-workers"
This interview was for a call center - the call center manager also attended my interview though she wasn't going to be my manager - she asked questions that were not relevant to the position - despite this I answered them anyway. Seemed like a waste of time or was just orchestrated by the main interviewer to fill time or to just have a second opinion of me personally.