05 Jun '20 15:48>
The post that was quoted here has been removedNow that I Google it, I do see that "abject lesson" may not make sense, though I've seen "abject lesson" used countless times when referring to lessons from very bad results.
Noted for future reference, though instead of saying "object lesson," if I had to do it again, I'd use a different phrase that better describes learning from bad results.