That was the subject line of reader S. Wallerstein's e-mail to me the other day sharing this charming story (Mr. Wallerstein lives in South America):

Many years ago a waiter in a café began to speak to me in Yiddish, a language I do not understand even though both my parents are Jewish and I was educated as a Jew. 

He did not look Jewish.  In fact, he looked Mexican. 

Jewish friends of mine explained to me that he was originally Mexican, but he had given himself a Jewish name, liked to be called by that name and had learned Yiddish (on his own) as well as bits and pieces of Jewish culture.   

I was  moved by his wanting to be considered Jewish and along with my Jewish friends, we treated him as one of us, invited him to our get-togethers, etc.  None of us were religious or attended synagogue, so this fellow's lack of interest in Judaism as a religion did not concern us.   

Apparently, because when he was "down and out" as a young man, some Jews had treated him with generosity and respect, he had decided that he wanted to be one of them,   of the Jews.  He himself was an extraordinarily generous person with a gift for language-learning, with little formal education. 

I've lost touch with him in the 40 years since I last saw him, but I have the highest opinion of him as a human being and he certainly embodies the Jewish virtues more than many who are born into that people.  I will consider him as a Jew all my life.