It is disappointing to me that many Jewish boys and girls (men and women as well) use the phrase “when I was bar/bat mitzvahed.” I have observed that many non-Jews use the term in same way.
The language to fully articulate the concept of bar/mitzvah is awkward and cumbersome. As a result, it has evolved to describing the ritual rather than the person..
The correct use of the term is “to become a bar mitzvah, and no party is necessary. Age is the only requirement (usually 13 for boys, 12 for girls). Reaching the age of bar/bat mitzvah signifies becoming a full-fledged member of the Jewish community with the responsibilities that come with it.
Bar (בַּר) is a Jewish Babylonian Aramaic word literally meaning “son” (בֵּן), while bat (בַּת) means “daughter” in Hebrew, and mitzvah (מִצְוָה) means “commandment” or “law” (plural: mitzvot). Thus bar mitzvah and bat mitzvah literally translate to “son of commandment” and “daughter of commandment.” Although the term is commonly used to refer to the ritual itself, the phrase refers to the person.
It is the practice in Conservative and Reform congregations for a boy to be called to read selected portions from the Torah on the occasion. In most Orthodox congregations, however, women are not called to read from the Torah.
There is much more to be said on the subject.
Peruse the Internet at your pleasure.