I can't upvote this enough. As has been attributed to the Roman stoic Seneca: “An enemy is a bad witness to your merits, but a good one to your defects.”

Doesn't that just mean that the merits will be unspoken and implied by what the enemy is saying as they speak to your deficits?

If I'm short with a bad temper, then implicitly I'm NOT a bad enough public speaker, or that would have been mentioned top of mind.