Zen and the Art of Martial Arts Maintenance

We don't have one of those "showroom" models, in terms of our way of doing the martial arts. You can't just get the finance, grab the keys, and roll her out onto the beckoning highways. The main reason for this is that we're still figuring out exactly how this classic vehicle fits together.
We can move, we can "use" tai chi chuan to a certain degree, and we know this from real experience of people trying to hurt us. So we can drive, a little. We're not like formula-one drivers or anything; we're not killers or MMA fighters or what-have-you.
When  you start to teach others, you look back over not just what you've learnt, but how you've learnt it, and you can't help but think: "Is there a better way? Where did we waste time? Where are the flaws, the blindspots? What would have helped us out back at the beginning all those years ago?" Of course, there's a certain amount of meandering that you can't cut out. Everyone has to put in the work at some point.
Going back to the vehicle analogy, we could say that everyone who trains with us gets to see the whole damned thing stripped, cleaned and assembled. They say there are two things you shouldn't see in the process of being made: laws, and sausages. But I think it's vital to know your martial art inside out in this way.
Zen and the art of Motorcycle Maintenance is a book which now is more often parodied than read, but it's one of my favourites. In it, the main character discusses at length the difference between the way he owns a motorcycle, and the way in which his friend owns one. His friend buys an expensive BMW, a machine expected to rarely break down, and therefore never bothers to learn its workings. When it does break down, it generates huge anger and disbelief in its owner, as well as incurring costly mechanic's bills. The teller of the tale approaches his motorcycle from the inside out, and when it breaks down he can adapt ad-hoc repairs, and tell what's wrong just by listening to the engine turn over. He doesn't freak out because he knows how to fix it, and what that involves.
A martial art can break down, become stale or let you down at the crucial moment. So make sure you know your art for yourself in your bones, and haven't just been sold a slick machine with a convincing warranty.