It's that thought process of saying you are going to practice said (Subject), which in return makes you care about how the practice turns out more so than doing the practice (Mileage Wise). So you might do some pleasing studies to look at but you only did a very small amount.
Opposed to the sketching process where you just enjoy drawing and problem solving what ever comes to your mind. So when you break that barrier you are taking what you learn and making that a part of your sketching process. Which in return makes you do more relaxed studies so you can see what you really know/retained.
Hopefully this makes sense. Having a hard time putting it into words
