My SO's a physician. This has been on her radar since January. By February she was advising our relatives who don't stockpile groceries, meds and toiletries to begin doing so, incrementally if necessary, but until they had enough to last them a month or longer.
One twenty-something with severe asthma listened to her. My parents, caregivers to an octogenarian, purchased extra essentials a bit too late and only received a fraction of what they ordered. But those in their fifties and younger generally replied "I can have Amazon overnight stuff if stores run out," not realizing almost everyone with Internet access across the entire world thought the same thing.
Our highest-risk relatives are in their sixties and older. The most obstinate -- coincidentally those with the most comorbidities -- were Fox News devotees convinced this was fake news, that the flu was worse, etc. (She assured them that was not the case. Nevertheless, they persisted.) She continued reminding them for weeks and they wanted none of it. As of yesterday my in-laws were contemplating cutting up old sheets to use as toilet paper if they can't buy more soon. They still believe coronavirus fears are overblown and this will all blow over in a week or two.