Keller distinguishes between the number of ways a person can contribute and the amount of worthwhile work that remains available. She acknowledges that her own circumstances limited some forms of activity, but she does not treat those limits as making useful action impossible. Instead, she focuses on the opportunities that remain and on the continuing need for purposeful effort.

The statement presents usefulness as something that can take many forms, even when an individual’s practical options are restricted. Its emphasis is not on ignoring limitations, but on recognising that meaningful contribution does not depend on having unlimited choices. Keller’s reference to “endless” work also suggests that service, learning and constructive action are ongoing rather than finite tasks. The broader idea is that a person can find purpose by concentrating on what can be done, rather than measuring their value only by the range of activities available to them.