It's about the bubonic plague, my friend in morbidity.
That's the rosey and the ring. At the end, all fall down.
Who, then, was Humpty Dumpty?
Humpty was looking after the craddle,baby and all!
yes that rhyme,rosey is something it includes the sounds of the death,wheezing breath and the posey's were carried as a "nosegay" to cover the stench...
morbid indeed!

PS: yet we continue today to tell our children these tales......