Usefullness. It came to me that I now fully understand the word "usfullness". When you have outlived your usefullness, you enter into the realm of "burden". From a stellar Military career to just being a burden to the effort. It seems that cascades to all realms of daily life to all around. And to find or "invent" a usefullness for you is all but impostible when there are physical limitations.