Annabelle from Eugene, OrThe intro contains a recording of an alarm clock saying, "Good morning!". This is possibly the Timex Speakeasy Alarm Clock. The same "Good morning!" voice can also be heard when one would dial the time service in Baltimore, 410-844-1212.
Me from North East, AzThis song is about going through a crazy night, and waking up the next morning and wondering what you were thinkin when you did it.
Will.I.am, literally dreamt up "I Gotta Feelin'." Said the Black Eyed Pea: "Have you ever had a dream where there's a melody in your dream? I'll wake up out of my sleep and record that! 'I Gotta Feelin' was one of those songs."