"One person is missing from Cornus officinalis" means that all the brothers in my hometown were wearing Cornus officinalis when climbing the mountain today, only to find that one brother was missing-the author himself was not among them.
Poetry appreciation:
The author seems to regret not that he failed to spend the festival with his brothers in his hometown, but that the brothers failed to reunite completely during the festival; It seems that it is not worth saying that a person is a stranger in a foreign land, but the shortcomings of brothers need to be understood. This is tortuous and unnatural. Followed by the torrent of feelings, a blue lake appeared, which seemed calm, but in fact it was deeper.