Were it but Me that gained the Height — A High Life

Were it but Me that gained the Height－1
Were it but They, that failed!
How many things the Dying play
Might they but live, they would!
(F.1025/J.1015)
[1] gained the Height:: she reached the height of her life.
[2] failed:: those who failed to enjoy life.
[3] the Dying:: those who desire extremely. play:: to ridicule, mock.
[4] live:: to live a life vigorously. they would:: they would really do the "many things" they desired.