No, my position is that a recoverable setback will nonetheless remain unrecovered if there is no restorative force driving the recovery.
A student who is bad at arithmetic will tend to struggle to learn trigonometry. A good teacher can realize this and allocate time to arithmetic practice instead. But this time has to come somewhere. As long as the number of teaching hours remains the same, they have to sacrifice something else. So if the students are all caught up in arithmetic, they will be behind in trigonometry by the same amount.
To fully catch up without sacrifices, students who studied less would need to study correspondingly more to compensate, but there was no concerted effort to make that happen, although the opportunity certainly existed.
A student who is bad at arithmetic will tend to struggle to learn trigonometry. A good teacher can realize this and allocate time to arithmetic practice instead. But this time has to come somewhere. As long as the number of teaching hours remains the same, they have to sacrifice something else. So if the students are all caught up in arithmetic, they will be behind in trigonometry by the same amount.
To fully catch up without sacrifices, students who studied less would need to study correspondingly more to compensate, but there was no concerted effort to make that happen, although the opportunity certainly existed.