Please spare me
In theory - but the next time that you fly, check out how many people ignore the safety briefing by reading a newspaper or the inflight magazine.
So what? It's always the same information, anyone who has flown more than a handful of times already knows how to fasten the seat belt, where the exits are, how to put on your oxygen mask if they drop down, the procedure for opening the emergency exit door, and so on.
If they were teaching me how to land the damn plane in the event that both pilots died and it was left up to me, then I'll listen intently each and every time because those would be some very complicated instructions, as well as being different on different planes. But the instructions they provide at the start of every flight are simple enough I could have followed them when I was five years old, so please forgive me for not giving it my rapt attention when they are repeated for the umpteenth time!
Think about this. Which is more likely to cost lives, people flying who have never heard the instructions provided before the flight, or people driving a car who have never been given instructions for what to do in case their car becomes submerged in water, stalls on a deserted road with below zero temperatures, has a flat tire on a freeway in a construction zone with nowhere to pull over, etc? No, this isn't an invitation for some nanny state solution of having a two minute safety presentation in my car every time I turn the ignition before I'm allowed to put it in gear...