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]
(..) Someone's been stirring the pot, sire. Gout playing up, sire? It's the damp. It's the only possible explanation. Get me a brandy. The mood of the people, sire, it's turning ugly. They're commoners, Alfrid. They've always been ugly. It's not my fault they live in a place... (..)2013 The Hobbit: The Desolation of Smaug