Inconsistent Statement

Zhao Yu had a drop too much and started to feel dizzy. Nonetheless, as midnight had passed, he lit up a cigarette and did another calculation. After some intense coughing, the system revealed that Zhao Yu had gotten a "Kan-Zhen" hexagram for the day. The explanation was: "Water and Thunder. Thunder hidden within water, equal in strength, indistinguishable by sound and shape, the man shall not be deceived."

It was still impossible to decipher the obscure hexagram explanation, but the Kan-Zhen hexagram had previously appeared before. Zhao Yu clearly remembered that on the day of his training, "thunder" appeared. He wondered if there was any difference between the two "thunders?" Up until this point, Zhao Yu had yet to figure out what "Zhen" represented? He could use this opportunity to study it carefully.