Disappointed, but Not Surprised

I’ve been reflecting on my own feelings regarding this “resignation” business. Thing is, I’m not angry. I know my previous post may have sounded angry, but I wasn’t. Disappointed more than anything else, really. When I pulled into the driveway & saw his car, I had a feeling what happened; I was not at all surprised.
What surprises me, however, is the fact that I’m not upset or mad. And maybe I shouldn’t be. I am concerned, of course. Could this be a sign of proper boundaries & emotional detachment on my part? Hmm…
Unlike with my son (being a minor in my care), I’m not responsible for him & his actions, and I think that is somewhat freeing. Am I crazy to think this way? The reason I ask is because I’ve never had a reaction (or non-reaction) like this before.