From time to time, the opportunity to do something passes permanently, meaning there is no way to go back to the situation before. A few example situations:
I submitted a term paper with a hard deadline. A week later, while re-reading my own work, I noticed that I had forgotten to delete a bogus draft line that was untrue and not even coherent. Too bad that there was no way to resubmit (and it had probably already been read and graded).
Both of my grandfathers died before I was conscious. They were the only people in my vicinity who knew anything about the field of study I am now in, so we could have had lots of interesting conversations if they hadn't passed.
While scrolling through the photos on my camera, I accidentally hit the permanent-delete button on a video clip of a once-in-a-lifetime moment.
When I think back to these things, I feel a very specific kind of emotion that seems adjacent to regret, but isn't quite the same. It's more a kind of lamenting of a tragic fate. The first example could perhaps be argued to be "regret about inaction", but I only noticed my mistake afterwards; it wasn't a conscious decision to make my error. Similarly, I had no hand (I hope) in the passing of my grandfathers, so I can't regret my own actions. In the third, it's not like I wanted it to happen, but it happened and there is no recourse. There's no point being sad, angry or anxious because there is no uncertainty nor fault; the situation is 100% irrecoverable, and I am completely powerless.
In Dutch, my native language, we would use the adjectives jammer or spijtig (like the French dommage) to describe similar situations, although they express a milder, more trivial version of it. In English, expressions that come to mind surrounding this emotion are "It's too bad that ..." or "It's sad that ..." or "I wish ...".
Is there a noun for this regret-esque sentiment?
