Here's my experience.
When some of my friends were frequently talking about their twice-weekly poker game, I heard them several times and starting thinking about if I might like to play poker. I ended up playing poker with them, twice a week.
Later, was flying home from a business trip in Vegas and wanted something to read on the flight. I ended up with three poker books. Later I put them in my reading room (bathroom). I was always reading *something*, and that month I read about poker. While driving or whatever, I'd think about what I read - think about poker. I ended up writing a poker- playing bot, spending quite a bit of time analyzing poker as I created software that played poker.
I doubt I would have spent thousands of hours on poker had I never starting hearing about it from my friends. I wouldn't have written poker software if I had read model airplane books.
Whatever book I get, I spend several hours reading about it, and several more hours thinking about it. Whichever TV series I'm into, that's what's in my head.
As a teenager, I was into heavy metal music. I constantly had heavy metal themes pumped into my head, so a lot of my thoughts were around topics in the lyrics.
Later, I started listening to Christian music. I find that when I hear a song about forgiveness, I tend to think about forgiveness. When I'm thinking about forgiveness, I'm more likely to forgive. I'm also more likely to be grateful for the forgiveness I've received, if that's what I'm thinking about because that's what I'm hearing on my way to work.
From my experience, it seems obvious that whatever I'm exposed to a lot affects what I think about. What I think about a lot tends to affect what I do.
Does that mean that if I hear you say the words "eat cheese" I'm going to immediately run to go eat cheese? Of course not? But if people are constantly offering me different kinds of cheeses, talking about which cheese goes well with what, I just might try some cheese every so often.
If my mind is on violence several hours per day, sure whatever I think about a lot is going to tend effect what I'm more likely to do.