A thesis statement using the three texts (two if you remove the title by Robert Fulghum--I could not seem to find, nor are familiar with, the text referred to in the question) wold combine the idea that many different types of texts can be used to illustrate identity. Robert Fulghum is an author whose work tends to self-identity and biographical stories meant to inspire. Evan HUnter's story, "On the Sidewalk Bleeding," tells the story of a sixteen year old who has been stabbed and is laying on a sidewalk bleeding in the rain. He contemplates the remainder of his life (not knowing that he was dying). "BY Any Other Name," written by Santha Rama Rau, tells of the author's experience in a British school (with a culture very different from the culture of her Indian home). Both texts, Evan's and Rau's, speak to what may bring about a questioning of one's own identity.
Therefore, a thesis statement which could be used to tie in the above named texts, or the ideas, is as follows.
Identity, a subject which has existed as a struggle throughout time, can exist as the focus of texts (from self-help to biographies to non-fiction). Authors who differ as much as their texts, such as Santha Rama Rau, Robert Fulghum, and Evan Hunter, all illustrate the concept and ideology behind identity.