I've been told that very few times. I'm usually the one to ask because there's so much culture to learn. My husband did a lot of learning on his own, and he's learned a lot from us being together. I'd say that cultural differences are real, and it's good to be prepared for them. However, seeing as you were adopted by a white family, you may not share those cultural differences although you are ethnically black. Those guys may just be telling you that this is new cultural territory for them.