Might you not be getting the causality reversed and it is actually your mood that is dictating the nature of your dreams. My guess would be you have some problems your subconscious is examining via dreams.

Doc: we are all interested in your bum

Me: my bum?

Doc: your bum, we want to stick six feet of hosepipe up there

Me: I don’t want that to happen

Doc: expect not, are you free next Tuesday morning?