My father and brother succumb to what I call the “Roomba Paradox” which is that any time saved by using the device is lost to simply staring at the thing operate.  My father has faithfully followed mine around to three rooms on our ground floor to watch the pattern and my brother will physically relocate dirt in front of his rather than just letting it roam about.  I appear to be immune to this phenomenon and in polling other Roomba owners the brake seems to occur sharply with those born in 1983.  Maybe additional data will narrow it to a particular month.