Hand raised.I always presumed the "karate is for life" thing meant that you CAN train all your life, as the training can be tailored to your abilities, limitations etc as you age, and as some aspects decline (athleticism etc), others can take their place and still be developed (like methods of power generation and other subtleties).
I didn't think it meant that when you start, you cannot stop or you're not a real practitioner..
Also another meaning: that the training in karate doesn't have an end point as there isn't really an endpoint. Thus, for life.