I took this picture on Feb 1 when I was flying back from Paris to Toronto.

Feb 1 was:

– 3 weeks after the first death in Wuhan was (officially) reported

– 2 weeks after the second death was (officially) reported

– 1 week after Hubei was locked down and all major entertainment venues in China, including Shanghai Disneyland and the Great Wall, were closed

– 1 day after the death toll increased to 200; Russia, Spain, Sweden and the United Kingdom confirmed their first cases of the virus.

During the SARS outbreak in 2003, Toronto was one of the hardest-hit cities. The memory is still fresh in my mind. Seeing how quickly the virus spread exponentially, it was very clear to me that this new virus, now called COVID-19, is another SARS except that it spreads even faster.

Therefore, I decided to wear my mask on the 8-hour flight because I didn’t want to take any chance. There were probably 10 people on this flight who did the same. Some people gave me a weird look (yes, I caught that) but I don’t really care about the stigma.

Since then, I have been wearing a mask whenever I was in a crowded space. Since the lockdown, when I really needed to go out (no more than twice), I have been wearing a mask.

Although WHO still stands by its recommendation to not wear masks if you are not sick, it really makes no sense to me. I understand that the surgical mask that I am wearing does not seal (and hence there will be leakage). However, even if it could only capture 10% of the virus-carrying particles, it would still reduce the probability of catching the virus (slightly) – in either direction (i.e. getting infected or infecting other people if I am asymptomatic).

In addition, even if wearing a mask would not help at all (I doubt), it couldn’t possibly make it worse. People might give you a weird look. Other than that, there is absolutely no downside.

Assuming using hand sanitizer, not touching my face, etc. could each reduce another 10%, all in a sudden the probability of getting infection could be greatly reduced because they all add up. Every little bit helps.

This is very similar to funnel conversion in running an online business. To improve the purchase conversion rate, one needs to improve on all parts of the funnel – from top (e.g. awareness) to bottom (e.g. intent and transact). We might only get 2% here and 4% there. However, if we could find ~10 things like that, the conversion rate could easily double and the curve would look much steeper (rather than looking flattened).

So, for your own and other people’s safety, please wear a mask if you could. It lowers the conversion rate and flattens the curve.

P.S. I know it is difficult to buy masks now, and if you could, please don’t hoard. I am lucky that our family has always had a box of masks in the house even before the crisis. But even a homemade one is better than nothing. Remember, there is no downside.