I know enough has been said to take the rescue Course, but I'll add my 2 cents. I'm a DM-certified recreational diver. The rescue class was the most valuable scuba course I've taken. It trained me to check for signs that may cascade into something that would later require self-rescue or for someone on my dive boat or dive group. The list of standard things to do in an emergency was strongly ingrained into my mind and I find myself going over them each time before a dive. The rescue scenarios were tried out to see how each of us would respond to an emergency (list og local police/medic numbers, UW search and rescue, CPR, call for help, arrange for medivac etc) and the later debrief was immensely helpful. The Medic First-Aid/CPR course was also very helpful not only for diving, but for other non-diving situations as well.
In short, it makes you a better, safer diver. If you still need convincing, PM me.
Dive safely.