I've been the kid that couldn't get my nose out of a book, fiction or non-fiction, from age 5.
I had to actively limit it to an hour a day because I was 'wasting too much time' reading hahaha.
Empathy is walking in someone else's shoes and that's what fiction is: experience and responding to life in inside someone else. You can begin to understand the mindset of the murderer, the quadriplegic, the suicidal, the refugee, the billionaire, the homeless, the compassionate, the psychopath, the fundamentalist, the transsexual, the chronically ill - and that changes your feelings and behaviour towards others.
If, say, a wheelchair-bound character in a book you're reading mentions how annoying it is when people say X or treat them like Y - you think about how to change your behaviour towards those in wheelchairs because it never occurred to you how they'd feel about it before.
I love the way you absorb a new idea or way of seeing things and you can't unlearn it. Your perspective has simply... broadened. You've put in another puzzle piece to your picture of life.
But Dumbledore and Charlie (Perks of Being a Wallflower) both whispered in my ear that it doesn't do to dwell on reading and watching and forget to participate in life.
You actually have to live what you're reading...