Is it normal if my mood shifts a lot?

It sucks having your mood change a lot, especially when it changes. Lets just say I go to a party but my mood feels boring, I don't want to do anything, when usually when my mood is good Ill do anything! So sucks for that party for missing out :P So what can I do to cheer myself up fast? because when all of a sudden I cheer up, I feel good! and like not a bore!