We go to the dojo and train. Ok, so what does that get us? We will show improvement in return for making the choice and effort to go practice. This can only be a good thing. As an American, anything that gets me up and active has to be counted an improvement. Going to the dojo to train means getting some kind of instruction in your art and being able to practice it. That’s good, but relying on the teacher to provide all of the direction in your training makes for weak, inefficient training and slow progress.
If we pick some fundamental aspect of our art to work on, whether it is entering, or timing, or posture, or movement, we can refine that aspect of the art while practicing whatever it is our teacher is focusing on for the day. This gives training more continuity from practice to practice, and gives something to focus on any time we think about our art, whether we are in the dojo for formal practice, or just thinking about it when we're supposed to be accomplishing something at work. We can either float through our training, or we can choose what kind of martial artist we will become.