The Golden Rule
"Do to others what you want them to do to you".
There is no universal agreement on what it takes to be an adult. However, probably everyone would agree that the golden rule would be the best foundation. The 4Sight "guidelines for being an adult" are based upon that rule, starting with oneself and moving outward.
It's worth noting that there are times when we become overwhelmed so we need to understand that self-absorption can be necessary. However, over the long run, we need to do for others. If we don't then we will end up being a drain on our society. Even the most independent person will have effects on those around them and that equation needs to be balanced for the health of the group.