Journaling/blogging is also a good practice. I write for my own sake (I don't share it out, in general) but I write as if for an imagined audience made up of people I know in real life. If the topic is technical, it might be some classmates or colleagues, other topics I have other people in mind.
Occasionally I share out what I've written, but directly not published on a blog. Presently, I'm doing some demos for work training sessions (sort of a rebalancing effort, we have some very skilled and knowledgeable people, but the knowledge isn't evenly distributed and we have some very new people to programming). So some of the things I've written in the past are becoming relevant, I'm retooling what I wrote (actually it's a full-blown rewrite at this point) to target this specific group and make examples more suited to this office than prior offices (programming is programming, except it's not, motivating examples should be relevant to the audience).
It's been tough to find, especially when you're busy. One observation I've made is that, since everyone has different interests, it's helpful to be willing to engage with other people's interests. Thus, you probably need to be willing to read books you wouldn't have picked up on your own.
I also have a blog with a small email list, but I suspect the deep conversations are more likely to occur in person with someone who you have an established relationship.
I've also always loved the idea of a book club but I've never joined or started one.
Actually sometimes you even start to doubt what you've read when it's hard to come up with a second source. For example I read in "Broca's Brain" that Thomas Jefferson refused to believe in meteorites, but could not find a second source.
If it’s an ebook on Kobo I highlight & maybe add a note, then import the notes into Calibre. I also read on mobile, listen with TTS, and listen to audiobooks (mostly fiction there, since I take fewer notes when it’s a strong narrative, and I’ve enjoyed being read to since before I could read). Notes help take the edge of the urge to discuss, and they help me remember for future discussions.
Like others have said, it helps to read what friends and family are reading if you want to share in the experience.
You could create a book club group if you want to discuss specific books, or try a Clubhouse room with the book in the title.