Not very helpful advice for any folks with ADHD. We forget to eat, organize parties, go to the bathroom, etc. It is unfortunate but entirely outside our control. There is no "natural way" for me to reach the things I value because my brain is a dragon trying to find more new and shiny gold to horde while ignoring everything else around him. If I leave myself to "natural ways" then I play video games, watch videos, or binge Wikipedia all day.
I'm not sure this is helpful advice for anyone, to be honest. "The goals you think are important actually aren't if you need any reminders or tools to get there!" is a bad take for the majority of people, I think. If it works for you, that's great. I'm jealous that things align that way for you. But I'm guessing that for the majority of people, that isn't the case.
I've talked extensively to friends about this because I see nothing. I can picture nothing. It's just a void. Interestingly, it hasn't always been this way for me. I remember when I was in elementary and middle school, I could take exams and see the page the answer was on in the textbook in my mind. I'm not sure when or how I lost it, but it's gone. I do sometimes dream in video, though.
For me, most of what happens in my mind is sound. I always "hear" music in my head, though my inner monologue doesn't have a voice. It's more like I just "know" what I'm thinking. I don't hear anything in my head when I read, which allows me to read pretty quickly. I'm not saying that I don't subvocalize or whatever, but if I do it it isn't producing any sounds in my brain.
Some people can apparently picture the scenes they read in books. See the beach, see the characters, etc. I have talked extensively with friends about this stuff and some of them say it's ultra vivid, like watching a movie in their mind. I find that wild. There is an anecdote about Richard Feynman and another scientist or mathematician and how they kept time differently. If I remember, one saw the clock in their mind and the other relied on counting aloud mentally. I'm not sure where I read it, sorry.
I know what you wrote was more or less rhetorical, but I thought I would answer anyway. I think it's the same general set of reasons that people are fascinated by serial killers. Or homicidal dictators, etc.
Some of it is fascination with someone who is so foreign to ourselves. These people had to make similar decisions to those we make every day and chose very differently than we do. They did things that most of us would never consider and did them often, whereas we would be wracked by guilt and regret.
Some of it is a sense of longing brought on by romanticization of the past, whether it be WWII or the Wild West or medieval times. Our lives are very mundane and books and movies are a way of escape. I think that tends to leak into other areas of thought. We ignore how awful those time periods actually were and to some degree wish we could experience life "back then." Distance in time also tends to soften our view of people.
Many of these sorts of people also did things that are inherently "exciting". He robbed and murdered. Both of these are things that would get your heart rate up and which Hollywood does it's part to glorify. We see the action and don't often think about the aftermath. These are the types of characters that stories are written about. Nobody is writing a good novel about my life as a software engineer or teacher or fast food worker, etc. There is a reason why good characters in stories are written the way they are. They take huge risks to get what they want at any cost. They live lives of adventure. They handle people who get in their way. Things we fantasize about when we get tired of dealing with work, making money, and being in the same place for years.
Not a terribly deep consideration of why, but these are just a few surface-level reasons.