As the introduction to the Loeb edition says, In February 45 [a year before he wrote De Senectute] the death of his adored and only daughter drove him into a frenzy of writing in an effort to forget his grief.
The writing was only effective for a while, as he ended up writing about his dead daughter.
mnli hypothesis: The writing was only effective for a while, as he ended up writing about his dead daughter. premise: As the introduction to the Loeb edition says, In February 45 [a year before he wrote De Senectute] the death of his adored and only daughter drove him into a frenzy of writing in an effort to forget his grief.