Because the process is not deterministic! It's the same for me and my sister: I'm an avid reader since I can remember, she rarely pick ups a book or a comic. Still we both were good at school and she graduated university with full marks, I got a PhD and taught for a while.

Many factors contribute to steer and nudge the developing minds of children in discovering what they like, but your mileage may vary because we're all different and our context can vary even in the same family. The same stimulus may elicit different responses. It's a reasonably well studied field and the correlation between parental reading habits+attitude and children's love for reading is there. I think I have a few papers on this saved somewhere, will edit if I find them.

>Their children see their parents reading books and tend to mimic what their parents do.

A million times this. If a child doesn't see their parents reading they probably won't be that much insipired to do it, they won't attach particular emotional value to it and they might have a hard time starting once they're adults. This matters A LOT.

Reading affected not only my career but my entire life.

Reading helped make me calm, rational, reasonably imaginative, able to consider different viewpoints. Reading, both academic works and fiction, made me the human being I am. Peering in the thoughts of countless people before me who cared enough to transfer on paper (or clay tablet, or sheep skin) what they had in mind made me passionate about writing, more helpful to the ones I love, knowleageable, toughtful and a (modest) writer and sociologist. Reading SF led me to physics, reading the bible led me to atheism, reading about videogames complemented my passion for them. Reading is literally living more lives than non readers, or a fuller one. Without my love for English literature I wouldn't know the english language well enough to have been a professional translator and that came to me through finding wonderful books to read.

So yes, it helped my career because sociology does not pay well in my country and I'd be living in the streets if I wasn't a sysadmin, if I didn't have this love for computers derived - you guessed - by my readings and my fumbling when I was a kid.

But to say that is, really, saying nothing.

His entire body of work is outstanding. There's no facet of the human condition the man didn't understand and describe with compassion and competence. If your BF likes murder misteries the Guards books are your best bet.