The protagonists in Judd Apatow movies don't generally have their stuff together. They are emotionally stunted, occasionally underachieving, unmotivated to change and often even border on unlikable. But whether it's Seth Rogen's stoner-entrepreneur, Steve Carell's 40-year-old virgin or Adam Sandler's depressed movie star, there has always been at least some separation between the actor and the character. 

That shield of fiction is pushed aside in his latest, "The King of Staten Island," in which Pete Davidson (a co-writer and producer on the film) lays bare many of his personal struggles for our entertainment and edification, from losing his firefighter father at the age of 7 to living with Crohn's disease, in this tale of a Staten Island loser who is more than happy to just drift.

It is the kind of personal project that could have gone wrong in so many ways. All you need is for the lead to lack a certain self-awareness or for the filmmaker to be too protective. But somehow, and despite its bloated runtime, Davidson and Apatow have made a film that is honest, entertaining and humane. That is no small feat considering Davidson's character Scott is one of the most unlikable Apatow leads (at least at first). 

Scott is angry at the world for taking his father away, although he tries to hide that behind a nihilistic stoner front. He lives with his mother Margie (Marisa Tomei) and refuses to commit to the local girl he's sleeping with (Bel Powley, channeling "Working Girl"-style Staten Island swagger). He knows he has mental health issues but doesn't seem to want to do anything about it. He doesn't have any prospects or passions. His friends are losers too. And he doesn't even really seem to care about his pie-in-the-sky career choice of tattoo artist (his lack of skills in that department provides a particularly funny through line).

But Scott is 24 and his youthful indifference is starting to turn into a full-fledged character flaw, which is why Margie gives him a push and then a shove out of her house to get his act together. She's emboldened by her new boyfriend Ray (Bill Burr). He's a firefighter too, which makes Scott crazy. When Ray takes him out to a baseball game with his fellow firefighters, Scott decides to rant to the guys (among them an excellent Steve Buscemi) about why people in their profession shouldn't have families. It's raw and uncomfortable and helps set the stage for what will come next for Scott. 

Apatow refuses to make short movies and thus "The King of Staten Island" is a bit of an odyssey that's packed with some well-drawn side characters (including Maude Apatow as Scott's sister) and subplots as well as some questionable and repetitive ones. It also curiously leaves some story threads dangling (like a few of Ray's serious shortcomings that his ex-wife tells Scott about). 

But it's a journey that does pay off and the film really hits its stride in the third act, in which Scott finds himself living in the fire station with Ray and starts to learn about both work and his father. 

It might seem silly to say, but Davidson is really good at playing himself. He never sacrifices honesty in the name of trying to make himself seem cooler or more sympathetic and you end up liking him more because of it.

What is so refreshing about "The King of Staten Island" is that there isn't some big Hollywood arc to it. Scott doesn't suddenly become a tattoo prodigy. No suspiciously put-together love interest descends to pull him out of his status quo. And there is no miraculous revelation that fixes him completely, just a few little ones. 

Davidson isn't everyone's cup of tea and no one knows that better than he does. It's that self-awareness that elevates this story and makes "The King of Staten Island" worth the watch. 

"The King of Staten Island," a Universal Pictures release, is rated R by the Motion Picture Association of America for "for language and drug use throughout, sexual content and some violence/bloody images." Running time: 136 minutes. Three stars out four.