Good question, and one that may indicate a good area for us to develop more fully. The short answer is that a capacity for restraint relies upon an internal sense of securitythe more secure you feel, the more restraint you can practice (we're talking here about a healthy self-care kind of restraint). That sense of security is related to an internal conviction that your needs will be met, even when you don't know exactly how they will be met. Without that conviction (i.e. anxious attachment), we function with low levels of hope about getting what we need. The act of restraint then feels sad, like deprivation. Analogy: When someone is hungry, their capacity for restraint around food depends in part on how much hope they have for getting the sustenance they need.