“This love is so deep it cannot be undone.”
“The past cannot be undone. At best it can be understood so, perhaps, it can also be forgiven.”
“What's done cannot be undone.”
“Evil can be undone, but it cannot "develop" into good.”
“What is done cannot be undone, but one can prevent it happening again.”
“No one knows very much about the life of another. This ignorance becomes vivid, if you love another. Love sets the imagination on fire, and, also, eventually, chars the imagination into a harder element: imagination cannot match love, cannot plunge so deep, or range so wide.”