When I received my cert's back in the early 80's, it was a one day class and was very informal. No hands on was required, all tests were written. As long as I keep teaching classes, I dont have to renew my cert. I teach 2 NRA classes per year and that keeps me grandfathered in the system.
I'm sure to get certified today, its a whole different program. Glad I got certified back in the dark ages.