How should I as an ex-Muslim woman respond to Muslim men who ask me where my hijab is?

The reason why I am asking this is because I was using uber and the uber driver who was Muslim asked me what kind of name I have, and I told him that it's a Muslim name. The minute I told him that my name is a Muslim name, he immediately asked me why I am not wearing a hijab. So, I would like to get some ideas on how to respond to Muslim men who ask me why I am not wearing a hijab if that happens to me again in the future. Also, when my mom was wearing a hijab and I wasn't another Muslim man asked my mom why I am not wearing a hijab.