Shoulding is a form of conditionality: if you don’t behave the way you “should” (according to the arbitrary dictates of some external authority), you will be deemed wrong, bad, or unworthy. Shoulding is also a common pseudo-power tactic.
Conventional parenting, schooling, and religious training are so fraught with shoulding that conventionally reared children eventually internalize the external shoulds and develop the habit of shoulding on themselves. Such a child is said to be “well-adjusted” but as an adult will have difficulty connecting with his or her authentic Inner Guidance.
Since shoulding is psychologically coercive, being should upon activates one’s counterwill. Adults who were raised with a high degree of shoulding may have an overdeveloped counterwill, which can lead to being oppositional, rebellious, defensive, passive-aggressive, etc., but counterwill does not get rid of the shoulds.