The oldest profession

I was trying to find a John W. Smith in the 1900 census of Atchison county, Missouri. He was a former sheriff, lumber dealer and member of the General Assembly. The John Smith listed wasn't the "right" one. He was 69 and the father-in-law of the head of the household. The thing that amused me was in the column marked Occupation, Trade or Profession, his was given as "Old Age."