I was waiting a long time for this one little exchange between the current versions of Batman and Jim Gordon, because Gotham City's top police officer gets to show that he's not a complete dumb-arse. From the viewpoint of the average person in Gotham, Batman's secret identity is probably tough to figure out. To John or Jill Q. Public, a billionaire CEO who seemingly gads about all over the world would be the last person to put a cowl and cape. But it was always tough to swallow that Police Commissioner Jim Gordon couldn't figure out who the Dark Knight was.
Secret identities are a holdover from the earliest days of superhero conceptualisation, a double life that plugged readers right into the fantasy that they too could superpowered and nigh-unbeatable. Attitudes shifted over decades, leading folks to openly question the plausibility and necessity of the alter ego trope. It hangs around not only because of nostalgia, but because it's a useful metaphorical tool when creators want to look at how world-saving can affect a person's life.
But there are lots of scenarios where hiding a secret identity can seem mean and the Batman/Jim Gordon one is one of them. In the latter-day iterations of the Batman mythos, it makes sense that Gordon wouldn't try too hard to figure out who Batman was. Even if the Caped Crusader was actually helping Jim Gordon fight crime in Gotham, it was technically the top cop's job to arrest Batman. But a don't ask/don't tell stalemate comes across as crueller after Gordon and Batman start trusting each other. Once Gordon puts that Bat-signal on the roof of the GCPD headquarters, Batman should ostensibly feel comfortable letting him in on the fact that he's Thomas and Martha Wayne's son.
This is Batman, though, and he just doesn't let people in. Unless, of course, he forgets who he is, like he did for the last few months. Gordon actually became a different kind of Batman while Bruce Wayne had amnesia and their meeting made it seem like Gordon had no idea that he was talking to his predecessor.
When Bruce resumed his role as Gotham's protector last month in Batman #50, there was a scene where he visit Gordon as he recuperated from injuries. When Gordon expressed sorrow that Batman couldn't stay at rest, he almost slips and calls him Bruce.
It's about as vulnerable as either man lets themselves be around each other. I like this moment -- and predicted it a while back -- because it's just sly enough to go unremarked upon, but also feels like Gordon knows that Batman now knows that Gordon knows who he is. I can't imagine this will instigate some massive change of status quo, what with new creative teams taking over the Bat-books soon. But it works to deepen the understanding between these two characters and intimates that Gordon's probably known for a while. Now, it's about Jim Gordon keeping his ally's biggest secret, instead of being unable to figure it out in the first place.