What are the mental effect of HRT for a non-TS person?

I've heard people say that if you are a TS, HRT makes you feel better, but if you are a CD'r, it makes you feel worse (something like that). Now I know that this is a vast over simplification. However, I have read many descriptions from transsexuals about how it felt to be on HRT but I'm curious about the 'mental' effects on non-transsexuals. I've heard people say if you start HRT and it's not for you, you’ll know it, but how? What does it feel like if it's wrong? Have any of you tried it and stopped because it was felt wrong? Or perhaps used it for some other reason while identifying as male? I would be very interested to hear what the mental effects were.