Hit a PR today on the bench (210 X 10) after a few weeks where I thought I wasn't making progress. I dropped down in weight today. Before my rep ranges were more in the 4-7 range on the max set. It occurred to me that perhaps I was getting stronger - just not enough to make a rep gain at the heavier weights. Obviously, going from 4 reps to 5 reps is a much more significant gain than going from 9 reps to 10 reps at a lighter weight.
This may be obvious to most but it really helped me understand the importance of dropping weights and to be patient in the lower rep ranges.