Once, a worker rang my doorbell at 8:10 am to repair the toilet. "I was expecting you early," I said, "but not so early."

What I added in my imperfect Chinese sounded like "I have not yet put on my clothes." In fact, shocked into my sense of propriety, I had quickly slipped a robe over my nightgown before opening the door.

Seeing the man staring at me wide-eyed, I realized that I should have said: "I have not yet changed my sleeping clothes for my day clothes." But I didn't make any correction. We were both embarrassed enough.

Over the last half-year before the Shanghai World Expo began, much has been said and written about Shanghai people, for whom wearing pajamas has become fashionable everywhere and anytime. I hear that there is a public campaign calling on people not to wear pajamas outside their house. Has it succeeded? I don't know as I have not visited Shanghai since.

When I came to China two decades ago, I tried to buy pajamas at the Silk Market for relatives and friends abroad. Vendors had no idea what a pajama was as the Chinese were used to sleeping in their underwear. Maybe it is foreigners' demand that has created a market for pajamas.

While for us Westerners, a pajama is linked to intimacy, many Chinese around the country, both urban and rural, buy pajamas not as sleepwear but for their comfort. A grandmother wearing a Mickey Mouse patterned pajama or an old man with Teddy bears on his can be seen easily, as they go to the market in the morning and the park after dinner; some even venture to cinemas and the subway. This is what makes a pajama party something unusual.

I have a friend in Beijing who is in her 30s and has a 1-year-old daughter. Today's young mothers can't make it alone with a child, and most of them hire a maid. Every time I visit my friend, the maid, who lives with the family, is in her pajamas. I find it weird, but I tell myself "she is at home".

My friend Ann is very elegant in her brand-name dresses, but I have seen even her in pajamas. Ann does not cook. It is her husband who usually does, but as he leaves on business trips often, the couple asked Ann's father to come from Shanghai and take charge of the kitchen. I have known the man since the 1990s and always thought he was not only handsome but good-mannered too.

On my last visit, I could not believe my eyes: When the grandfather opened the door, with the baby in his arms, he was wearing cotton underwear. I had a chance to discover he was also very sexy! Looking away, I apologized as if I had done something wrong.

Had he come to the door expecting someone else? Not at all! I was embarrassed, but he was not. "Come in! Have a seat! Ann will be here in a moment," he invited, and instead of running directly to his bedroom, he also sat and started a conversation. Then appeared my friend - in her new dress and all well made-up.

If you insist on knowing my opinion, I would say one would not wear plastic sandals to a dinner, nor the most attractive bathing suit to go to the bank. It is only a matter of convenience and taste.