"For example, when you attack me with a straight punch, what I can feel is the force of that straight punch," Grandpa Qin explained. "That is known as external energy."
"However, if you can conceal different variations within your straight punch, variations that are invisible to others but can be felt, making them difficult to defend against, that is known as internal energy!"
While sparring with Lu Wenrou, Grandpa Qin used easy-to-understand language to tell her about the difference between external energy and internal energy.
"Grandpa Qin, I get it!"
Lu Wenrou suddenly had an epiphany; she had previously touched on the edge of internal energy but always felt as if there was a thin barrier preventing her full understanding.
Now, with Grandpa Qin breaking that barrier for her, she had an on-the-spot realization and stepped over the threshold into the realm of internal energy.
"Hmm, try attacking me with internal energy!"