dan would honestly feel better if jaekyung just changed his attitude towards him. the whole root of dan behavior comes from jaekyungs misdirected rage. u can see it after dan came back to the gym, the very first time jaekyung snapped at him for no reason, dan ended up falling back into his sleepwalking again
It would be more realistic if they got better together. That's how it'll be irl, that's just how it works. And KD didn't sleepwalk because jaekyung snapped at him lol, but I see your point but it's not really that realistic cause they're both not well in different ways. But your vision is a good one compared to the other ones

YOU. ITS YOU WHO HAVE TO CHANGE.