There are many different things that a hard boil type knot with no core on the lower part of the back could be. It could be infection.
A doctor will be able to tell you.
Because at the end of the year the students get them back.
The slip knot it a class of knot that goes back before recorded history. A link is provided to the Wikipedia article on the slip knot.
That could be a 'Windsor' or a 'Double-Windsor' knot.
Just a possibility: you have lymyph nodes back there which could be swollen due to some infection your body is dealing with. It could also be a clogged lymph node. Either way, probably better see a Doc.
because they both had a tied knot and had a huge reward for untieing it
pull it back out
because IT SUPPOSE TO BE IT SO THE KNOT WILL NOT BE SWINGGY AND YOU FALL
It is probaly a infection. You should see a doctor.
The knot appeared one day and Mr.Cobble thought he could use it to get buisness. Whoever untied it got their picture in the newspaper and a free large pizza ...
because the cumiliations in the hair cells are all tight so that is what can cause it to knot