same here im stretching it to close to 3 years, gonna have it done in october. I also did the same for the cabin filter.
My dad, who doesnt service anything until things start to break, never changed a fluid in his life aside oil changes. he had a 1990 audi that got it's first brake fluid flush after 14 years (only because i started driving it and decided it was time for a tune up). and a mazda3 that's 9 years old that is also still on the original fluid. he doesn't drive much so the cars had less then 150k on both combined.