I tripped.
While I was fidgeting due to my current weakened stats, I didn't focus where I placed my feet and tripped. And got KO-ed. Have I been reduced to back when I was a Grey Demon or something?
This all comes down to the night after the day we sent boss-spider-san to the ice age and I stupidly thought it was safe to take the [Poison Immunity] skill, but it turned out to be the final straw on the camel's back.
I got slapped with the Waning ailment.
Waning refers to the waning of the soul due to it being overloaded with skills, which turns out to be like the proverb I just used. Skills can be seen as equipment for the soul, which allows it to access the latent power in it that all souls have. However, I've over-equipped my soul! Like how a child cannot wear a solid iron plate-mail, my poor soul couldn't handle the stress of the skill-festival I have going!