The point of a guide is that they know of things that aren't in the guidebooks. :) It's like if you came here, I could take you to eat at the almost literal hole-in-the-wall Mexican place run out of someone's garage (grandfathered in when zoning laws said you couldn't do that any more), and show you the small tree beside Highway 30 that someone decorates with seasonal and holiday-appropriate decorations, but neither of them would be in the guidebook.

And if you were driving, you wouldn't see either of them: the restaurant because it's in a neighborhood where there's no reason for you to go, and the tree because you'd be too busy paying attention to the road and coping with unfamiliar traffic signals to see it.

That's why I like getting a guide.