"mi'e" is used when you are telling somebody your name. There is no country where everyone speaks Lojban, so nobody is born with a name in Lojban. But, some Lojbanists make up lojban names for themselves that they use. Because they know most other people do not speak lojban, they usually keep their real name as well, and only use their lojban name when speaking to other lojbanists. If someone is telling you their real name, they usually say "mi'e la'oi" (sounds like "miheh lahoy") followed by the name.