Who is a Han Chinese?

Cheong Suk-Wai of the Straits Times wrote a review of Anthony Milner's book "The Malays". In it she cites the Basham Professor of Asian History at ANU as saying ' the struggle for Malay identity through the ages has been such that it is as hard to say for sure who is Malay as it is to say who is not.'

It just made me wonder if that is not true for any other ethnic definition?

After all....who the hell are the Han Chinese?

Wikipedia says:

Han Chinese (simplified Chinese: 汉族 or 汉人; traditional Chinese: 漢族 or 漢人; pinyin: hànzú or hànrén) are an ethnic group native to China and, by most modern definitions, the largest single ethnic group in the world.

Han Chinese constitute about 92 percent of the population of the People's Republic of ChinaRepublic of China (Taiwan), 75 percent of the population of Singapore, and about 20 percent of the entire global human population. There is substantial genetic, linguistic, cultural and social diversity among the subgroups of the Han, mainly due to thousands of years of immigration and assimilation of various regional ethnicities and tribes within China. The Han Chinese are a subset of the Chinese nation (Zhonghua minzu). An alternate name that many Chinese peoples use to refer to themselves is "Descendants of the Dragon" (Chinese: 龍的傳人 or 龙的传人). Many Han and other Chinese also call themselves "Descendants of the Yan Di (Yan Emperor) and Huang Di (Yellow Emperor)" (Chinese: 炎黃子孫 or 炎黄子孙).

Locally we usualy don't even use the term but refer to Chinese as "Tang Ren 唐人".

Wikipedia further points to the fluidity of the Han concept:

'The definition of the Han identity has varied throughout history. Prior to the 20th century, some Chinese-speaking ethnic groups like the Hakka and the Tanka were not universally accepted as Han Chinese, while some non-Chinese speaking peoples, like the Zhuang, were sometimes considered Han. Today, Hui are considered a separate ethnic group, but aside from their practice of Islam, little distinguishes them from the Han; two Han from different regions might differ more in language, customs, and culture than a neighboring Han and Hui. During the Qing Dynasty, Han Chinese who had entered the Eight Banners military system were considered Manchu, while Chinese nationalists seeking to overthrow the monarchy stressed Han Chinese identity in contrast to the Manchu rulers.

Whether the idea of Han Chinese is recent or not is a debated topic in China studies. Many Chinese scholars such as Ho Ping-Ti believe that the concept of a Han ethnicity is an ancient one, dating from the Han Dynasty itself.

So let me ask you..... how do you know you are Chinese?