Too Difficult
As we’ve already mentioned, Sherwood Schwartz and Robert Reed would feud many times over the quality of the scripts. Schwartz later said that if the show had been renewed for a sixth season that the character of Mike Brady would have been completely written out of the show as Reed had become too difficult to work with.
Brownie
Out of all the Brady children and parents, Christopher Knight who played Peter was the ~only~ cast member with brown eyes. Everyone else had blue eyes.