Most of us have been on the MTR or a bus when a fellow commuter coughs or sneezes nearby. Ordinarily we think little of it, but in the shadow of the Covid-19 pandemic, our survival instincts go off like a siren. You don’t want to be that person but you move away anyway, shut your eyes, hold your breath and later, when circumstances allow, wipe your face, hands and any exposed body parts with alcohol wipes. A few days ago, my part-time domestic helper was late, explaining that her husband had been coughing and she had taken him to a clinic. My immediate response was to ask her to go home; what if her husband was infected with the coronavirus? But I let her carry on, a decision I may regret. We will know within 14 days, won’t we? Anxiety has become a familiar emotion. While a little anxiety keeps us from potential harm, too much of it, or when it descends into paranoia, can affect our mental and even physical health. There’s a Chinese saying to describe the excessive suspicion of people or things: bei gong she ying , or “the bow in the cup; the reflection of a snake”. One version of the origins of this saying appeared in Comprehensive Meaning of Customs and Mores , a book written around AD195 by Ying Shao. It includes a story about the author’s grandfather, Ying Chen, a district magistrate. One day Ying invited his assistant magistrate, Du Xuan, for a drink at his residence. Hanging on a wall at Ying’s house was a bow, which Du saw reflected in his wine and mistook for a real snake. Despite being gripped by fear, he did not dare rebuff his superior’s toast and downed his wine, “snake” and all. That same day, Du came down with severe chest and stomach pains. He tried various remedies to no avail. Some time later, when Ying visited his deputy on official business, Du said he had become sick after ingesting a snake. Ruminating over Du’s words back at his house, Ying lifted his eyes to see the bow hanging on the wall. Realising what must have happened, he sent a carriage to fetch the bedridden Du and placed him at the exact spot where he had sat previously. He gave Du a cup of wine and, sure enough, the “snake” appeared in its surface. Pointing to the bow on the wall, Ying revealed the source of Du’s illness and, just like that, Du’s misgivings were allayed and his ailments vanished. In these uncertain times, don’t be Du Xuan, who suffered unnecessarily because of his overactive imagination and paranoia. Take the necessary precautions: frequently wash your hands, do not touch your face, wear a mask if you feel unwell and practise social distancing. Do not spread rumours or forward unsubstantiated information. Try to get used to the new uncertainties, and calmly get on with life. And know that this too will pass.