When better to establish that long term behavior when there is an immediate, credible threat? Even if it does slightly increase pressure on the medical mask sup

When better to establish that long term behavior when there is an immediate, credible threat? Even if it does slightly increase pressure on the medical mask supply (who will be prioritized with the certified masks, regardless), how many lives will this save in the next pandemic? Or every flu season, for that matter. It seems unrealistic to think Americans will start wearing masks everywhere after this has all blown over if they were not previously conditioned to do so.