Be aware of different cultures

For the first time I met a girl in the club whose culture does not allow her to shake hands with men. Although many are the times we are asked to be cautious of different cultures, I was quite ruffled by having to withdraw my extended hand. For a while I did not know what to do with it. I did not know whether to apologise for attempting to shake her hand or not. But, thanks to table topics, I guess I did mumble all the necessary noises as per the "moment of truth" requirements of our club. Next time I will be more careful.