We can all get into a funk (as I've already demonstrated!), but as long as we can keep looking on the bright side we're okay.
...always look on the bright side of life! (whistle)
Always look on the bright side of life... If life seems jolly rotten, There's something you've forgotten! And that's to laugh and smile and dance and sing,
When you're feeling in the dumps, Don't be silly chumps, Just purse your lips and whistle -- that's the thing!