The most shocking thing I learnt (well it was more of a surprise than a shock) was that some deaf adults who use sign language prefer to have deaf children so that they can pass on their language and culture. A hearing child would just not fit in. This might seem really odd, but I met many wonderful deaf families, with several generations of deafness (i.e. it was inherited and genetic) and they were really worried about having hearing children. To them, being deaf was totally normal and being hearing was a problem. They were quite happy being deaf and all used sign language together.