Why Can't I Focus Anymore? The Science of Attention Decline

This is a boring an answer, because you can't make any money off of it, but I've started to read the classics and listen to classical music. It's a weird process because it's hard to measure (which is probably what makes it effective). But I sort of assume getting some of this back means slowing down, trying to focus on things that are hard to focus on, and trusting the process.