The speaker looks back on a love or passion so intense that it may never return, and the poem moves through that feeling in short, broken fragments. The mind keeps circling around "ceremonies of sorrow," as if grief has its own rituals that won't let go. There's a sense of things left unsaid: words that "die" before they're spoken, and letters that can't be delivered. The strange line about letters "unfit to deliver / a child" suggests that something important, maybe a new beginning or a bond, can't be carried across.
Then the mood shifts. The image of wind and a match making love in a cloister is vivid and a little shocking: fire and desire invading a place meant for restraint and quiet. The last lines return to the body, which stirs in the very place where the speaker "lost my head." Longing and regret sit side by side. The title, French for "lost time," fits the tone: the poem feels haunted by what was missed, yet still warm with desire.