My Papa's Waltz

I find it hard to decipher if one line out of an entire poem could be the most meaningful, but if I had to choose... it would be the very last line.  "Still clinging to your shirt."  It's not as detailed as the previous lines where Roethke spoke of the scent of whiskey and a battered knuckle.  Instead there is an innocence to this last line.  It's as if the child were taking note of all the faults in his father, but ignoring them because this "waltz" or rhythm of life is comforting to him.