Paris Jackson Celebrates 19th Birthday Like Regular Teenager

Paris Jackson's birthday looked like a typical teen's Monday -- eating Mickey D's, smoking cigs, hanging with friends -- which is a full 180 from when she was a kid.

She celebrated 19 by chillin' outside a friend's apartment ... possibly the most casual party ever for Hollywood royalty.

Can't blame Paris though for toning things down. Her childhood was nothing short of a media circus ... hidden behind veils, paparazzi and bodyguards at every turn.

She's earned some normalcy. Happy 19th, PJ!