Just for the sake of clarification and because it seems to be a 'forbidden' topic in JW circles...
Let's talk psychology and the definition of sanity and not sanity.
In 'life', by the loose (but accurate) definition of western medicine, 'sanity' is nothing more than this:
"Can you take care of yourself without hurting anyone else?"
Beyond that, no one cares if you think the moon is made of green cheese or Charles Russel is playing the bongos in your pantry.
No one is mandated to step in and help you and no one can legally stop you, as long as...'you can take care of yourself without hurting anyone else'.
Another very simple but much more useful definition of sanity, I think, is this one:
Can you remember your past?
Can you cope with the present?
Can you plan for the future?
Anyone having trouble with any of these will rather quickly see in which department their trouble lies.
For all those many places in between, I very highly recommend the book, "The New Personality Self-Portrait; Why You Think, Work, Love and Act the Way You Do" by Oldham (you can read about it online at Amazon or other places).
It's very positive and oriented toward a better understanding of youself (and others).
Feel free to comment.