You may not understand why the door closed until you see what was waiting behind the next one.

The reason a closing made sense is often only visible from further along, and there is no way to fast-forward to that view. In the meantime you are asked to keep moving without the explanation, which is genuinely hard and not a failure of character when it feels impossible.

Rather than demanding the meaning now, take the next available step and let understanding arrive whenever it does. Keep a note of the questions you are carrying. Some of them get answered in a way you would not have believed at the time.