The Internet is the world’s greatest collection of knowledge, but increasingly, that wisdom lives in walled off apps. It lives in services and platforms. Places where we build up relationships, express preferences, and reveal so much about ourselves. We’re on Foursquare and Netflix and Facebook and Twitter and Skype. We’re interacting in real time, and in ways that don’t lend themselves well to indexing. Google can’t know exactly what’s going on in all those places. How the links between entities work. What and who we like and dislike. There is information there that it can’t index. And if it can’t index it, or understand it, it damn sure can’t serve an ad.

Trouble is, that hard-to-index information is key to Google’s future. Mountain View may not be all about search anymore, but it desperately wants to be able to answer real world questions for you; there’s a huge difference. Search is just about retrieving information. Actually answering subjective questions requires a deep knowledge of the person doing the asking: Where you are, who your are friends, what your interests are, what you like and don’t like.

Picture this scenario. You are about to leave San Francisco to drive to Lake Tahoe for a weekend of skiing, so you fire up your Android handset and ask it “what’s the best restaurant between here and Lake Tahoe?”

It’s an incredibly complex and subjective query. But Google wants to be able to answer it anyway. (This was an actual example given to me by Google.) To provide one, it needs to know things about you. A lot of things. A staggering number of things.

To start with, it needs to know where you are. Then there is the question of your route—are you taking 80 up to the north side of the lake, or will you take 50 and the southern route? It needs to know what you like. So it will look to the restaurants you’ve frequented in the past and what you’ve thought of them. It may want to know who is in the car with you—your vegan roommates?—and see their dining and review history as well. It would be helpful to see what kind of restaurants you’ve sought out before. It may look at your Web browsing habits to see what kind of sites you frequent. It wants to know which places your wider circle of friends have recommended. But of course, similar tastes may not mean similar budgets, so it could need to take a look at your spending history. It may look to the types of instructional cooking videos you’ve viewed or the recipes found in your browsing history.

It wants to look at every possible signal it can find, and deliver a highly relevant answer: You want to eat at Ikeda’s in Auburn, California. Hey, I love that place too! Try the apple pie.

There is only one path to that answer, and it goes straight through your privacy. Google can’t deliver this kind of a tailored result if you’re using all kinds of other services that it doesn’t control. Nor can it do it if you keep your Google services separated. You have to do all the things you used to do elsewhere within the confines of one big information sharing service called Google.