Thanks for the reply!

I actually don't normally think of bad/inappropriate thoughts, it's just when I try to suppress a particular kind of thinking it will cause that thought to bubble to the surface.

When I think 'everybody can read my mind, I better not think of anything inappropriate', it's like my subconscious mind takes that as a challenge to bring forth the most inappropriate thing imaginable (like the apple example I gave).

But your right, I'm sure there are many people over there who can't control their thoughts. They must be used to it.