uptown与downtown一般情况下中文说:乡下.为什么在英文中downtown反而是市中心的意思呢

这句话有语法错误吗,
i'm uptown girl
i has been living in my uptown world
and now i'm looking for a downtown man

英语翻译
she’s been living in her uptown world
i bet she never had a back street guy
i bet her mama never told her why
i’m gonna try for an uptown girl
she’s been living in her white bread world
as long as anyone with hot blood can
and now she’s looking for a downtown man
that’s what i am
and when she knows what she wants from her time
and when she wakes up and makes up her mind
she’ll see i’m not so tough just because
i’m in love with an uptown girl
you know i’ve seen her in her uptown world
she’s getting tired of her high class toys
and all her presents from her uptown boys
she’s got a choice
oh!oh!oh!oh!oh!oh!oh!oh!
oh!oh!oh!oh!oh!oh!oh!oh!
uptown girl
you know i can’t afford to buy her pearls
but maybe someday when my ship comes in
she’ll understand what kind of guy i’ve been
and then i’ll win
and when she’s walking
she’s looking so fine
and when she’s talking she’ll say that she’s mine
she’ll say i’m not so tough
just because
i’m in love with an uptown girl
she’s been living in her white bread world
as long as anyone with hot blood can
and now she’s looking for a downtown man
that’s what i am
uptown girl
she’s my uptown girl
you know i’m in love with an uptown girl
my uptown girl
you know i’m in love with an uptown girl
she my uptown girl
you know i’m in love with an uptown girl
my uptown girl
you know i’m in love with an uptown girl
she my uptown girl
you know i’m in love with an uptown girl
(end!)

downtown,uptown和midtown的区别?
请不要复制词典的内容!最好给出一些例子来,