I didn't take it that way. They're just pointing out that it's impossible to set those boundaries with young children. The poster they're replying to has a full time stay-at-home spouse providing for the kids during the day so they don't have to be interrupted, yet they're implying it's something that anyone could easily do. A 4 year old might not be capable of leaving you alone for a solid hour as time seems to pass glacially slow to someone at that age. Telling them to leave you alone for an hour is like telling your wife to leave you alone for 48 hours.