Being focused while reading does not come naturally to human beings. It is a skill that requires practice. At least in my experience this is true. I start by turning off the TV and putting my phone on the other side of the room so I won't reach for it every few minutes. If I listen to music, it has to be quiet and non-vocal. Then I really try to focus on the story that's being told to me. My mind naturally wanders but I keep pulling it back. Trust me It gets easier over time.