Is my phone listening to me?

I was aware that such situations exists that even your voice while having your phone in your pocket could be used to get information for personalized ads, but recently I was surprised by how far it went...

Annoyed by odd volume numbers...
It happened recently at work and (interestingly) with switched off WiFi and no mobile coverage at the place I was working. I was having the phone in the pocket while I talked to a colleague and he was telling me that he always gets annoyed by the volume settings on the radio if an uneven number is used. Either 12 or 14 is fine, but neither 13 nor 11! He claimed that many people where having this issue forcing them to correct the volume every time.

Although the conversation was in German, the following day Facebook suggested me a video about the exact thing in English where people discussed that in a car! Coincidence?

Talking about a certain software?
Or: Recently I had a job interview when I was asked about having experience with a certain software. A few days later Facebook suggested ads showing exactly that software and other products of that company. And I wasn't using any WiFi, I only had connection with via mobile data.

Apparently companies like Google and Facebook are denying such things. But secretly the situation could be different and it's definitely interesting.

What are your experiences? Let me if you had similar situations in the comments!