"New approaches to performance mean change, and preparing people for change is the business of training and its only justification." (Gilbert, T. 1982. "A Question of Performance Part II: Applying the PROBE Model." Training and Development Journal)
We commonly think about training as a solution to teach people things. Redefining training as "preparing people for change" is very compelling to me. I think that it really helps people focus on the performance impact that training has.