I Have Made But One Mistake

From Zanecorpwiki

Emperor Titus's last words are reported to be, "I have made but one mistake." (Well, it was in Latin, which I can't find.) Contemporary historians generally think the mistake was not killing his younger brother Domitian, though the impression I get (from secondary sources) is that it was enigmatic to them as well. If those were indeed his last words. Later historians speculate it could have been a reference to his getting involved with a certain women, or breaking it off, and other things.

Mike Duncan likes to believe that Titus was referring to something trivial, like forgetting to water his favorite date tree.

For myself, I would place my bet on the mistake being not having trained Domitian. This would fit perfectly in the narrative. Titus was a mature, sophisticated leader who was no doubt aware of his brother's shortcomings. It would also be a nice bit of enigmatic foreshadowing.