Describes a complete emotional process.
"Slightly happy" means a preliminary understanding and recognition of some people or things, which may not be comprehensive and profound enough. "Quiet love" expresses deep liking and affection for certain people or things, but does not want to express it too openly or excessively. "Understanding deeply" means having experienced a profound emotional process and having a high level of knowledge and understanding of emotional issues. This is a kind of understanding and perception of feelings from shallow to deep, from initial liking to deep love, to understanding and understanding, which represents the sublimation and deepening of feelings.