Ups and downs with smiles and frowns. . . or ""A smile can hold dreams/ and all sorts of wishes./ But not a frown!/ Frowns are like upside-down dishes."" The illustration of this proposition puts a bad face on every curve that faces down, be it ""a bump that's/ been made by a bee,/ or the lump that appears when you've banged up your knee."" Or the shell of a crab or the beak of a dodo or hawk (""the birds that smile are the birds that sing""). None of this of course holds up when you bear down on it (""happy"" mustaches take negative forms, a clock doesn't time its smiles) any more than black and white. Laugh it off.