Chapter 14 of The Untethered Soul is titled, letting go of false solidity. In an effort to create the illusion of stable environment we create a false mental model of the world that suits our preferences and then we cling to it. We cling to what want and we cling to what we don't want as well. Obviously this creates suffering by constantly trying to control our lives that are constantly changing. Singer explains several different  familiar conditions of life that cause suffering and the solution is Always the same. Be the one that is aware of the familiar conditions and the suffering.