Or maybe your kids/family are different from other peoples'. I've seen some peoples' kids who were a complete terror and nothing could make them stay calm and quiet. Some kids are just better than others that way. You got lucky. This is a big reason I never really wanted kids; I just can't handle constant noise and commotion. I have a friend with a 7yo kid who's bouncing off the walls every time I visit; there's just no way I could live with someone like that every day. I have enough noise and commotion at work; I don't need it at home too.

And yes, open offices are horrible this way too. That's why we're having this discussion about people wanting to work from home: for many, it's a lot better than the chaos at the open-plan office at work, even if it isn't ideal. For others, it's at least as bad (kids/wife), so they either deal with the office, or they go to a coffee shop or rent a coworking space or similar.