朝 (zhāo): Morning or dawn. It sets the beginning of the daily cycle.
思 (sī): To think of, to miss, to long for. This is a deep, contemplative kind of thinking.
暮 (mù): Evening or dusk. This marks the end of the day.
想 (xiǎng): To think of, to want, to miss. This is a more active form of thinking or wanting.
Together, these characters create a perfectly balanced structure: [Time 1: Morning] + [Action: Thinking/Missing] + [Time 2: Evening] + [Action: Thinking/Missing]. This illustrates a continuous, unbroken cycle of yearning that lasts from the moment you wake up until you go to sleep.