I had to resuscitate a man the other day who'd choked on some food. He went down like a sack of -er- spuds. It's astonishing how quickly it happens when you run out of O2 and it's unexpected. Sometimes you need to pull, on other types you just strap on. Another reason it's worth paying attention.
In the case of an explosive decompression, just think about all the crap that will suddenly become airborne - well, I mean airborne with reference to the interior of the aircraft. I can only think of three survivable, notable EDs; one was a fan blade that busted the fuselage when the pilots were playing with CBs, the UA flight which took a few pax out, and the convertible Hawaiian flight. There must be more.
It would be interesting to learn how many people have died because they've not known how to use their O2. Not that many, I think. There's that flight in Greece a few years ago where a slow leak incapacitated the pilots, and the FAs arrived too late.
SO