Billy: Hey kid, why are you sad?
Orphan: Oh, I'm waiting for my parents.
Billy: Oh, and how long have you been here?
Orphan: About 200 years.
Okay, so listen up, numbskull. The joke is funny because the orphan says he's been waiting for his parents for 200 years. Orphans don't have parents. So they are either joking or delusional. Since you probably believe everything you read on the internet, I'm guessing you'd be waiting a long time too if you were an orphan. Get it? Good, now go back to drooling.