cpr

There are two things you want around if you ever suffer a sudden cardiac arrest or a heart attack.  One is an Automated External Defibrillator (AED) and the other is a person who can administer CPR.  Without these, you have little chance of surviving a heart-stopping arrest. 

There is a good chance that you will personally witness a cardiac arrest in your lifetime.  For me, that's enough of a reason to hope that everyone knows CPR (especially the guy standing next to me if I suddenly drop dead).  Without it, you have little chance of surviving a heart-stopping arrest.