I think we were all shocked, regardless of whatever age. In 1995, I was nine, and Vader's act of severing Luke's hand horrified me. When he revealed that he was Luke's father, I was scared out of my mind. "Me, too!" My Mom was in her forties at the time. Additionally, I knew that Vader was telling the truth, since the beginning of the VHS tape of TESB featured Leonard Maltin asking Lucas how people reacted to the moment when they learned who Vader "really is."