Should also get a bike, they reckon it's a better guard against Alzheimer's than walking.
Probably because of the requirement for constant situational awareness. My paths have enough people on portions of them that 'on your left' is my most frequent refrain followed by 'heads up' to people who can't look down at their phone AND walk a straight line. Before they built two way bike lanes, curbed off from both vehicular and foot traffic, it was near impossible to 'matriculate' my way amongst NU students walking between classes......heads gazing downward at their phones.