This quote is talking about how the people you surround yourself with can have a strong impact on how you feel and live your life. Caregivers are people who are generous and empathetic and they tend to attract people with similar traits and values. This creates a community of love and appreciation that energises the caregivers, making them fulfilled and happy with life. On the other hand, when a person is selfish and always looks for what they can get from other people (without caring about what they can contribute) then they tend to attract and be surrounded by people with a similarly negative outlook. This can lead to their resenting those around them, feeling that their good deeds are not appreciated, and feeling tired from giving with no return.