The forty-something black man I was sharing an elevator with looked at me for a while before he asked the question I had been expecting. He wanted to know my ethnicity.

"I'm mixed," I told him. "Half-Caucasian, half-Asian."

"Oh," he said, disappointed. "I thought you were one of us."

I knew what the question would be because people have been asking me the same thing as long as I can remember. I've found that curiosity easily overrides courtesy. I am asked in stores, on the bus, on the street, in line at McDonald's, even in public bathrooms. Almost always the inquirers are total strangers, as if not knowing me allows them to abandon social graces they might otherwise feel the need to display. Sometimes they will ask me straight out, but very often they use coded language, as in "What's your background?" Then there's "Where are you from?" which is really a two-part question, to be followed by "Where are you really from?"

Why is it that people feel they can approach me for this personal information? Would they ask total strangers their age or marital status? What do they need the information for? Are they census takers? Once, in a truly surreal episode, a casino dealer stopped in the middle of a hand of poker to ask me, as if he couldn't stand to wait a second longer. After I offered my usual answer, he shook his finger in my face and said he wasn't convinced, that I didn't look white enough. He was Asian.

I wonder why, after having been subjected to this treatment for years, I still respond. I can't remember a time when doing so has resulted in a pleasant encounter or a meaningful conversation. Yet I've never quite found the strength to meet such inquiries with "It's none of your business" or, better yet, silence. What's quite strange is that people often feel the need to comment, as if what I've told them is an opinion they can't quite agree with. Comedian Margaret Cho tells a story about a TV producer who asked her to act "a little more Chinese," to which she replied, "But I'm Korean." "Whatever," the producer said. I had a similar experience with a man in a bookstore, who crept out from behind a shelf of cookbooks to ask me where I was from. Before I had a chance to say anything, he guessed: "Japan?" I could have said Oregon, where my father is from, but I knew he wouldn't go for that, so I said, "Indonesia." "Ah," he said. "Close." It's not close. Not really. Not unless you consider London close to Djibouti. The distances are similar.

In the game of "Name that Ethnicity," I am the trick question. I have been mistaken for almost every Asian nationality, but also as Hispanic, Native American, Arab and, of course, African American. There's something in being a chameleon. It's human nature to look for unifying bonds. When people think that they have something in common with you, particularly something so personal as identity, they feel they know you and they imagine that you have an innate understanding of them, too. They will speak to you in a certain unguarded way. The idea that any person can be truly "colorblind" is a fallacy. As long as the human eye can detect differences in skin tone, eye shape, hair texture, these differences will play a role in how we interact with one another. Because of my ambiguous appearance, I have experienced from people the kind of familiarity they would normally reserve for one of their "own."

The unfortunate consequence of this ambiguity is the misunderstanding I frequently encounter from those who haven't gotten the full story. The Mexican immigration official who looks disgusted when I can't understand Spanish, as I surely should. The kindly Vietnamese waiter who helps me "remember" how to pronounce the names of dishes. This puts me in the slightly ridiculous position of being apologetic for not being what people expect me to be, however unreasonable.

When I think back to the man in the elevator, I feel disappointed, too. The way he said "I thought you were one of us" made me feel as if we might have bonded but now couldn't, as if I'd been refused entry into a club because I didn't have the right password. My immediate reaction was that I was missing out on something. But I see the artificiality of this classification mentality. If the opportunity for bonding existed before he knew my ethnic makeup, wasn't it still there after he found out? After all, I was still the same person.

When my parents were married, my grandfather was against the union. His objection was that the children of mixed marriages had no foothold in any one community but instead were doomed to a lifetime of identity crises and disorientation.

If my grandfather were still alive, I'd tell him that the crisis comes not from within, but from without.

I know who I am. It's everyone else that's having trouble.