When love is at its best, one loves so much that he cannot forget.

The line frames “forgetting” not as a failure of will but as a measure of love’s depth: at its fullest, love imprints itself on memory and identity so strongly that erasure becomes impossible. It suggests that enduring recollection—of a person, a bond, or even a loss—is an intrinsic consequence of profound attachment. The quote also implies a hierarchy of loves (“at its best”), distinguishing passing affection from transformative devotion. In this view, memory is not merely sentimental; it is evidence that love has altered the lover’s inner life, making the beloved persist as a continuing presence in thought and feeling.