Who Trains the trainers?

There is a way to describe learning styles as a balance between pragmatic and theoretical, reflector and activist. I am it would appear an activist and learn best by "getting stuck in".
I've been getting stuck in to becoming a trainer in general practice and recently enjoyed the experience of taking part in the initial trainers course.
So who is it who trains the trainers?
The team I have met so far are a blend of all the above learning styles, but in addition they all share an ability to inspire. Each one of them is unique, but common traits emerge.
They are all enthusiastic about primary care. They are all committed to empowering the future trainers to create the best environment for new trainees.
Combining the opposites of ambition with practical achievements, inspiration with governance and reality with motivation is not easy. The breadth of sessions covered has already been significant.
But in answer to the question- who trains the trainers? - it's easy- bloody good GPs do the training.