Some people have excellent parents and environments. These parents raised their children first by protecting them and loving them unconditionally. These children were able to develop a sense of self and were eventually allowed to face difficulties with the ever present eye of their protector over them. Through their childhoods, they were able to develop their own self-soothing, self nurturing behaviors. They learned to trust themselves and others and were allowed to go out into the world to manage their own lives.
Other children were raised with parents who likely never learned how to protect and love in this way. Or they grew up in difficult environments that kept their parents from having the ability to provide these things. These children find themselves inadequately prepared to trust and love themselves, let alone others. Many of these people are very compassionate to everyone around them, but unable to show themselves the least bit of care.
There are others who were over protected and never allowed to go out into the world and fail. These people never learned they were capable of caring for themselves. They often do not trust themselves, but feel someone else must take responsibility for them.
Learning self-care is such an important skill. This may be the toolbox I pull out most often. Sometimes I lose track of these tools… Keeping a notebook of tools is a very good idea.