Nancy Mairs has multiple sclerosis, and therefore refers to herself as a cripple. Mairs does now view cripple as a negative word. Instead, in the passage, she describes the word cripple as "a clean word, straightforward and preside." In the passage, Mairs presents herself a "tough customer, one whom the fates/gods/viruses have not been kind, but who can face the brutal truth of her existence squarely. "She uses this metaphor to show people how tough and strong she still is after accepting her life as it is.
Another reason Mairs refers to