It's hard to relate to someone who has such wild/extreme 'mood swings'. [=someone whose mood changes very quickly]
She turned down the lights and lit a candle to create a more romantic 'mood'. [='atmosphere']
I'm sorry. I'm just not 'in the mood to talk'. [=I do not want to talk to anyone right now]
(..) It rains because you're sad, baby. It's not fair. Never is. We are who we are... ...even if we sometimes forget. Jeff, I am so not in the mood for you! Get back in the subway! Now! That's not good. Wait! No! Jay! (..)2002 Men in Black II