I think that there's a clause here, as in "it depends."

Because it depends on who is listening, and how you are perceived. If I write about what I do for a living, which is adventure travel, and I can back up every single claim I make, it's not bragging because it's what I do. However I get accused of that regularly. That's different from bandying that information around to belittle or one-up someone else, which is indeed malignant. There are people who will accuse you of bragging because their egos are just that delicate, for example. So I would challenge this to say it's a lot more complex and subtle than this. I have friends who, like me, are pilots and scuba divers and explorers. Our conversations are amazing and nobody's bragging, it's what we do. That's lively. Bring in someone who doesn't and that person might accuse us of bragging. So, it depends. bragging is a matter of perception as much as it is a matter of intent. I do dislike the idiot humble brags on Linked In where it is an art form. But that's its own category.