He learned who I was from watching me when I did not know I was being watched, doing things I had no reason to do for any audience, being kind to people who could not report my kindness to anyone.

That is the only place true character is ever visible: in the unwatched moment, in the thing you do when there is no one to see it and no advantage to be gained from it.

Everyone performs virtue when virtue is rewarded, or witnessed, or expected.

The performance tells you nothing.

What tells you everything is what a person does in the moments they believe are invisible, when kindness earns them nothing, when there is no one to impress and nothing to gain, when the only reason to be good is that they are good.

Julian, from his window, had access to exactly those moments of mine.