My father (WW2 RAF Halifax crew) always used to speak about feeling "the bump" as the wings took the weight a few seconds AFTER leaving the ground. As a kid I used to argue with him that this was a nonsense and the wings must have fully supported the weight by liftoff. But he persisted, and he had the experience ! In later years I figured he might be speaking about leaving ground effect and that it was maybe a feature of that airframe you could feel at high weight. But it could also have been a feeling as the aircraft rotated.
Now in a commercial jet, if you are behind the centre of gravity, as the aircraft rotates your seat angle will change and you will feel you are being tipped backwards. That will give a sensation of being pressed into your seat as your relative g changes during the rotation, and you go down below the CofG, and it will feel like a drop. Up front you will rise up above the CofG
A more obvious "drop" happens during noise abatement where the rate of climb is reduced, and again there is a relative change of g you experience.
Interested to hear what others say.
BTW, back to the Halifax, I gather that if they managed more than a 1 degree climb angle (not certain about the associated attitude) it was a good set of engines !