Two pieces of string meet one day in the park and
while one goes on the slide the other goes on the
swings. They're having a great time until one
string decides to go on the roundabout.

After a while, the string feels really dizzy and
falls off, scraping across the tarmac and making
as tangled mess of one end and falling in a heap.
The second string looked at him and sighed
"you're not very good on that roundabout are
you?"

The first string looked at himself and said "I'm
a frayed knot".