Reliving Nursery Rhymes

I have always been interested in story books and nursery rhymes when I was younger. It is funny how our memory works. Those nursery rhymes that I used to recite just stuck to my memory and got stowed away. After having baby Dan, slowly but surely day by day, the nursery rhymes that were stored at the deep far end of my memory started to reappear, twinkle twinkle little star, baa baa black sheep, mary had a little lamb. Even those that were not quite popular at that point of time.

Now looking back, nursery rhymes were just rhymes to us that we recite. As an adult, trying to literally interpret it, most of them have a tragic end. Here are some

Baby falls from the cradle from the tree?

Rock-a-bye baby, on the tree top.

When the wind blows, the cradle will rock.

When the bough breaks, the cradle will fall.

Down will come baby, cradle and all.

Poor Humpty Dumpty...

Humpty Dumpty sat on a wall,
Humpty Dumpty had a great fall.
All the king's horses and all the king's men
Couldn't put Humpty together again.

Jack and Jill rolling down the hill?

Jack and Jill when up the hill to fetch a pail of water

Jack fell down and broke his crown and Jill came tumbling after.

This makes me wonder what is the criteria of nursery rhyme selection and whether there is a moral behind it.