Who needs Patty Cake anyway?

It seems like lately everytime someone new meets Emma they always ask "Can she do patty cake?" I stand there not knowing what to respond. The simple answer is no, she can't. However, the reason she can't is because we've never taught it to her. I guess I missed the memo that part of childhood development is every child knowing how to do patty cake. When someone asks the questions and then tries to initiate patty cake with Emma I get defensive and start rambling "She doesn't know patty cake but she can can do all the actions of the bumble bee song and itsy bitsy spider." Is this normal that all mothers get defensive about their child's abilities? Am I overly sensitive to not wanting people to think my child is "slow" because of the population of children I work with? Part of me wants to practice patty cake with Emma all weekend long so the next opportunity that comes up she can make her debut. But the other part of me wants to just say "Who Cares!" I guess it's all about priority. The liklihood of Emma learning patty cake from me is pretty slim. However, check back in a couple of years and I bet she will be able to moon walk like no other child!