Sydney Smith (1771-1845), letter to Sir Wilmot Horton (February 8, 1836):
I am going slowly down the hill of life. One evil in old age is that, as your time is come, you think every little illness is the beginning of the end. When a man expects to be arrested every knock at the door is an alarm.
See also his letter to Mrs. Crowe (January 5, 1840):
Among the many evils of getting old, one is, that every little illness may probably be the last. You feel like a delinquent who knows that the constable is looking out after him.