Things that they did not know...
[OP: ]
=> Weapon Arts: Affinity rank: S+
=> Aura affinity: AA+
=> Leadership: Affinity rank: AA+
=> Command and tactics: A++
…
=> Caretaking: C+
=> Loyalty: S
=> Solder training: C+
=> Knight training: A+
=> Music understanding: B+
The results of his grandpa's assessment were out and they revealed something unique about him that even he did not know about…
"I always had an affinity for these things or does this show how much affinity for something I possess right now?"
"It's the current one. They cannot be from some specific time in the past since these affinities are something close to experiences one has obtained."
To put it in simpler words, these experiences had become something close to an affinity that helped them with these tasks naturally.