How many warnings do we need?

Every year around winter there is a CO danger commercial every 1/2 hour. And as for boats I can't imagine the number of warnings that are in the manual and on the dash board of nearly every boat I seen that says, "MAKE SURE THERE IS NO ONE BEHIND THE BOAT WHEN THE ENGINE IS ON" and "TURN OFF THE ENGINE WHEN PICKING UP SKIIERS"

According to the Naval Safety Center "The symptoms of CO poisoning may include severe headache, dizziness, confusion, nausea, fainting, and death. Low levels can cause shortness of breath, mild nausea, and a mild headache. Low levels are more dangerous in the boating environment because they can lead to drowning. Carbon-monoxide poisoning may not be suspected immediately because the symptoms are similar to those of people with the flu, food poisoning, or other illnesses. If you suspect CO poisoning, immediately get the victim to fresh air and seek medical care."

"Many victims who survive have permanent brain damage. Anyone in the water without a PFD who is rendered unconscious will drown immediately." 

Even with this warning Teak surfing without a PFD is popular. Go figure. 

Seems that despite all the warnings people make mistakes, it happens, lets hope that someone learns from it.