I can confirm that smart phones listen to everything you say. I tend to bring up a bunch of random conversation topics with my wife, as I am as full of useless trivia, among other things. Sometimes I'll see an ad and be like, "WTF?" Then I'll remember the conversation from the day before. That's creepy.
The other side of it, though, is that I carry a device the size of my high school calculator in my pocket which can instantly access most of existing human knowledge, sort of like a modern Library of Alexandria. It can also get me around traffic jams before I get into them and prevent me from getting lost. Fair trade, IMO. The ex-libertarian in me doesn't like the spying, but whatever. I don't have much of a choice anyway, because I have to use a smartphone for multi-factor authentication to do a number of things, including work. I'm a little annoyed by that, but I have zero leverage to push back. I'll just rate having the phone as a net win with some downsides.