Saki says that youth is like hors d'oeuvres: you are so busy thinking of the next courses you don't notice it. When you've had them, you wish you'd had more hors d'oeuvres.
Philip LarkinHeads in the Women's Ward On pillow after pillow lies The wild white hair and staring eyes; Jaws stand open; necks are stretched With every tendon sharply sketched; A bearded mouth talks silently To someone no one else can see. Sixty years ago they smiled At lover, husband, first-born child. Smiles are for youth. For old age come Death's terror and delirium.
Philip Larkin