Butterflies fall with flowers and swallows fly with water.
The scenery described in the previous sentence of Late Spring, although beautiful, hides the hidden worries of youth, but this is only an undercurrent, and the poet is subjectively unaware of it.
Your endeavors smiled.
With a "shock", the poet suddenly thought that years had passed and friends were scarce, which instantly opened the door to emotion. Hidden in front of the undercurrent suddenly gushed out, showing ups and downs, full of tension beauty.
My humble opinion is for reference only.