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.
Another problem is that people often use the wrong fluid when they change it. This even happens at shops, trust me. Often times transmissions, even by the same manufacturer, will use different fluid and the wrong one can cause premature failure.Sometimes people use what is cheap, which can be a problem for the same reason.any mechanics believe, perhaps correctly, that if you wait too long (mileage, not color) you should not change the fluid because it could cause transmission failure prematurely; whereas if you had changed it regularly all along it would be ok. People differ on what that mileage might be, but let's say it's 100k miles.