My question wasn't to pilots, it was to fellow SLF regarding how often they have experienced having to stop themselves hitting the seat in-front.
In today's landing, most passengers had to take visible action to avoid head-butting the seat infront! I guess those who didn't were braced more firmly in their seat. I'm just curious as to how often this occurs - and as already mentioned above - not very.
I'm sorry I can't provide any more technical details.
Informed passengers are well aware that there are 2 people up front; one usually "less qualified" than the other; so of course this fact is going to be used in jest. Posts from flight crew frequently jest about it too, so I don't see why SLF shouldn't be allowed to!