ugh Murray...that's a tough one. My dad and his friends used that tactic with me, and it is so ingrained that I consistently watch for it in real life. The most helpful thing for me has been a short list of people that I trust to tell me the truth. I carry it in my purse, this is exactly what it says:

If I am not sure whether something is real, or I am being told that I imagining things, I can trust the following people to always tell me the truth. They care about me a great deal and would never hurt me. It is ok to listen to them and do what they tell me to do.
1) H - phone number
2) Daughter - phone number
3) G - phone number