You bet I do and I regularly get recertified. I am CPR qualified for special cases like infants too. It all started with a course in the military and I have kept the knowledge current - which is a good idea as the methods periodically change (for instance now it is straight compressions without pausing for breaths).

While I have not had occasion to use my CPR skills I have had to use my First Aid training repeatedly.

I also have knowledge of low level and high level (wilderness) rescue and field first aid.