What YQY learns in his formative years is that a reckless rescue is not only just as bad as no rescue at all, it's WORSE.

YQY has these lines during his confession to SY, while talking about his own impulsive nature, and how he's tried to keep it in check all this time:

Was YQY worried about qi deviating after SQQ died? Was he training to make sure he didn't do anything impulsive, in case total war broke out between the major sects after LQG retrieved SQQ's body?

When discussing the conflict between HHP and CQM, a nameless side character put it like this:

But here, when LBH attacks the sect, Mu Qingfang says that YQY's secluded cultivation was forcefully interrupted.

So in my interpretation, this means that SQQ's five years of "death" are what triggered YQY into secluding himself, and it was probably in the Lingxi Caves.

Perhaps that line wasn't meant to signify anything, but if YQY tried to avoid the caves because they triggered traumatic memories, it would make sense. He gets weird about it when Shen Yuan merely mentions that he'll be secluding himself:

So what was Yue Qingyuan doing during those five years that Luo Binghe held onto Shen Qingqiu’s body?

Well, here's my long-winded attempt at analysis.

First off, as far as the original SQQ knew, YQY never went into seclusion (trust me this is relevant):