FWIW, it was the birth of Berlin's (and his wife Ellen's) daughter) that inspired him to write this song.

Minor lyric correction:

Blue Skies smilin' at me,...
Nothin' but blue skies do I see.
Bluebird singin' a song,
Nothin' but blue skies from now on.

Never saw the sun shinin' so bright,
Never saw things goin' so right.
Noticin' the days hurrying by.
When you're in love, my, my how they fly.

Blue skies smilin' at me,
Nothin' but blue skies do I see,
Blue day, all of them gone.
Nothin' but Blue Skies from now on.
...