"What of soul was left, I wonder, when the kissing had to stop?"

In this quote, the speaker is reviewing the after-effects of a passionate kiss. They question what stays of the soul once the physical act of kissing has actually ended. This might recommend that the kiss was so intense and consuming that it left the speaker sensation empty or incomplete once it was over. It might likewise imply that the kiss was a short-term escape from reality, and now the speaker is left to face the harshness of the world again. Overall, the quote highlights the power and significance of a kiss and the effect it can have on one's soul.