I know that feel.
Host used wayy to low weight for - the past year I guess.
We were basically stuck with the same weight the whole time. Ok, we increased reps but still. It's amazing as you said - we start with low weight, then quickly increase, and miraculously after a few minutes rest it's possible to do more reps with even more weight in the last two of the 6x we do the exercise. The body adapts.
I tried something else and let host do 2x push on consecutive days, with a lot more weight than before. It felt good, soreness is minimal so far. Maybe tomorrow?
But yeah, you just gotta up that weight and reps.
I'm not complaining, the body can take a lot more than a year ago, I just noticed we focused too much on reps and not enough on weight.