Okay lwj didnt play wuji to sizhui when he was little, sizhui remember wuji because wwx played it when he was little and I HAVE PROOF

Exhibit A: Jingyi doesn& #39;t recognize the tune. It& #39;s not heard often in Clud Recesses
Exhibit B: Sizhui doesn& #39;t recognize the tune. If LWJ played it for him, he would know it was LWJ because he only had contact with him after 3 years, so he was 7. He remembers everything from 7 on

Exhibit C: Lan Wangji himself tells WWX that he hasn& #39;t EVER played that song to anyone, which is why it& #39;s such an effective way of recognizing him.
Exhibit D: WWX plays it in three situations.
1. He& #39;s nostalgic and missing LWJ and he& #39;s secluded with nothing else to do while the

juniors are working. This is a common mood for him in the Burial Mounds, so he probably used to play it a lot.
2. He& #39;s trying to calm Wen Ning down. He chooses this tune as a calming tune because it was what calmed him down on the cave. A-Yuan is a child and Wen Ning is a

unstable puppet if WWX isn& #39;t careful back in Burial Mounds, so it& #39;s very likely that he played it for both of them to calm them down, if not to calm HIMSELF down.
3. He& #39;s like "what should I play now?" when he and LWJ are going around on Little Apple and he plays that.

It& #39;s really his favorite song, he plays it all the time.

Sizhui doesn& #39;t quite remember when he heard it because he has amnesia, but he heard it in Burial Mounds.