These are some common definitions of "CARE":
In the provision of what is necessary, seems like sending a card in the mail would contribute to the health and welfare of a lonely Grandparent. I guess if someone just feels concern or interest in
another person, they wouldn't need to take any action to express that feeling. They could experience that feeling and not share it with the one they were concerned or interested in. So according to the first verb definition of care, someone on the outside of a relationship may not be able to know that one person cares about another. That is a personal experience of feeling and does not, by definition, require any action. I imagine that it is potentially uncomfortable for a person to feel concern or interest in another person and not express it. This discomfort may manifest as anger towards those who are actively expressing their feelings of concern through action. It may manifest as guilt and gossip.
From now on, I will find a better word than care. I want to do more than just care about people from afar. I want to be involved in their life. I don't want to sit back feeling concern or interest in someone and allow it to go unexpressed.