What do you mean by drifting in a tree hole?

Drifting tree hole is a space bearing thoughts, blessings and venting emotions.

Drifting tree hole refers to a big cave, in which many drifting bottles and all kinds of garbage are piled up. Drift bottle is one of the limited means of communication when people cross the vast sea. Historically, people put information, gifts, etc. Put it in a bottle and throw it into the sea to drift to an unknown distance with the ocean current to convey information or express emotions.