They ask A lot of questions to determine if you really are whom you appear to be. Eg. They want to fish out if your pretending to be a tourist or jewish etc. I know from experience.
I was asked if I was Jewish, and then I was quizzed on various observance practices. Since I am observant, I was able to answer all their questions instantly and accurately. I guess they were convinced that I was who I said I was, since they let me in for a glorious vacation.