Can one feel too attached? Does one need to let go to mature? Neural stem cells have this problem, too.
As immature cells, neural stem cells must stick together in a protected environment called a niche in order to divide so they can make all of the cells that populate the nervous system. But when it's time to mature, or differentiate, the neural stem cells must stop dividing, detach from their neighbors and migrate to where they are needed to form the circuits necessary for humans to think, feel and interact with the world.