Make Useful In All Things
One aspect of training martial arts is making it useful not only for the obvious purpose, but useful in all things as it relates to how we live our lives today.
Many times, when viewing through the lens of historical function and modern context, its connection is actually not all that distant. (Sometimes it is, of course, but I digress.)
For example, the context of time, environment, tools, or priority over one another may momentarily be altered, but its true purpose of a martial system, when fully understood, should fundamentally and ultimately serve the need of the moment without need of drastically changing its core essence.
In some ways, its purpose can be hidden, as if it were built to have its own intrinsic system of trap doors, snake pits and caverns only accessed by those that perseveringly search, and are ready, for its true meaning.
[ Okay, now cue Raiders of the Lost Ark theme song ]