Kai Syaoran entered the green bamboo forest and this time, he ventured deep into the tall bamboo and as he walked, he let his mind wander from one thing to another. At some point, he even started thinking about useless things such as the bamboo around him. As he thought more and more about bamboo, he realised that it was not useless at all, at least for humans, it was very useful. Kai had seen many human houses constructed using bamboo.
He realised that there was nothing useless in the world. To some people, something may be extremely useless and to some other people, the thing may be of great use. What any person wanting to be successful needs to do is find someone in need of things that are useless to them and exchange them for what they consider to be useful.