Mr Miyogi's Bonsai, from The Karate Kid

Mr. Miyagi, of the movie "Karate Kid," is a bonsai enigma.
Mr. Miyagi gave Daniel, the hero of the movie Karate kid one, a bonsai tree. But this occurred on the first meeting of Mr. Miyagi and Daniel. Furthermore, Mr. Miyagi offered Daniel a tree for his mother, someone he had never met.
Mr. Miyagi had eight trees visible in the movie. Since he was an apartment building manager, I assume this was his whole collection. I do not understand why Mr. Miyagi was so generous with his bonsai "children." I thought he must have hated some trees and wanted to get rid of them; but he actually gave Daniel a choice of what trees to take. Whatever, Mr Miyagi.
Also, in the third movie Mr. Miyagi takes his prized bonsai and plants it in the wild, in a deep crevasse by the sea shore. Daniel tries to recover this masterpiece left by Miyagi years ago, only to drop the tree in seawater. Miyagi nurses the tree back to health, as any bonsai adept could do.
My Question is: what would you do with your best bonsai when you are perfectly healthy and have lots of time but no-longer want to do bonsai? I bet that bonsai would go to a good home and artist, and would not be abandoned in the wild.
This also shows Daniel had no clue about bonsai: a bonsai tree with 5 year wild/field growth, and it's a pine - this would not fetch a good price on any market. The branches would be leggy.