- I had my own room as a kid. My parents and brother banged on the door whenever they pleased.
- I worked at a tech company, had my own desk, and wore headphones. Coworkers still sent me Slack messages and tapped me on my shoulder.
- I've lived in a home in the burbs. People came to my home and rang the bell.
None of them were hard for the interruptor to do, and all of them happened frequently. In fact, I would argue that they are more frequent than the number of phone calls I get nowadays, which are actually easy much easier to screen/ignore than any of the above interruptions.