Easy, buy his latest edition. Like all of us, he's still learning. Personally, I like Palmer's "How To Brew" better, but I have a 1995 edition of Miller's book and it has its points.
There is a very good book series from Brewers Publications that are titled like, "Brown Ale" and are great for someone trying to refine a favorite style.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk