TNF - agree 100%.
When pax start paying attention every time then we can all relax. It never ceases to surprise me how totally unaware my fellow pax are. Not just about the briefing but as to where in the flight time-line we are / that food is being served and the aisles blocked / that the seat belt light is on / etc.
Over the past 20 years, the carriers have made a big thing of "Hey - it's just like a bus, you turn up and sit down and there you are!" that now we have generations of pax who have no idea of what is involved. Should they know? That's a long discussion that has been held before on Pprune.
So keep up with the amusing introductions and I would go further, add the words "Your life may depend upon your understanding of this information." Nope, never going to happen because no carrier will whisper that something might go wrong! My greatest concern about an emergency onboard is the danger to me from my fellow pax. They terrify me.
I refer you to the thread about an emergency evacuation from a QF 744 upon arrival at SYD - now running in the main Rumours section.