Many non-Japanese conflate sashimi and sushi; the two dishes are actually distinct and separate. Sushi refers to any dish made with vinegared rice, and while raw fish is one traditional sushi ingredient, many sushi dishes contain seafood that has been cooked, while others have no seafood at all.
It's the moisture and contaminents that break down the DOT 3 and 4 fluids which is the reason to change the fluid in the first place. If you don't change it, what happens is moisture enters the system via the vented fill caps on the brake master cylinder. This moisture along with dust, mixes and travels in the system eventually making it's way to the lowest points in the system.
Also, if you put fresh brake fluid, even from an unopened container, under a strong vacuum, youâll find that it has dissolved air in it. If done right, you can deaerate brake fluid before putting it in the car. Other reasons you may need to change brake fluid more frequently is if you track your car.