People tend to call 911 while they're having a heart attack; but a first heart attack doesn't tend to kill people, so if they live through it, they tend to think it isn't an urgent problem in need of calling 911, and instead just go to the hospital at their earliest convenience. The problem here guilt/shame delaying "earliest convenience."

Washing your hands and covering your mouth while you cough is obvious too; that doesn't mean the messaging is unnecessary.

It isn't obvious, unless you happen to suffer from hypochondria.