I have a friend named Mike who is thinking kind of strange. He has told me recently that he has quit both of his jobs (one of them was working at a community college as a professor) and that everything including himself is "no thing". He also says that everything is just a concept and that nothing is real. I asked him how he is going to pay for food, rent, or other bills and he became very defensive. I am wondering if he is going into escapism or worse mental illness. Any advice would be appreciated. Thank you