CANNES, France — Joanna Hogg is sitting on a hotel balcony overlooking the Mediterranean, but what she'd really like to be doing is swimming in it. 

The night before, Hogg premiered her film "The Souvenir Part II" at the Cannes Film Festival. Sequels may be a regular part of summer, but they rarely make it to Cannes. Yet "The Souvenir" is no usual two-parter. 

Together, the movies are a sublime, singular work of semi-autobiography — a coming-of-age self-portrait reflected through time and cinema. They're based on a period in Hogg's life in the late '80s when she was in film school in London. 

In part one, a romance with an older man who has a hidden drug addiction ends tragically. In part two, Julie devotes herself to making her final student film about that experience while processing her grief. In both, Honor Swinton Byrne plays a slightly fictionalized version of Hogg when she was younger; Byrne's real-life mother, Tilda Swinton, plays her mom. 

The movies were written together as one piece, spread across two films. And there's very little like them. 

"I don't even feel sure I have completed it," Hogg says, a little surprised to feel that way. "It's funny, because I have completed it. I'm not making another part. I don't know that it's really dawned on me that it's finished."

"The Souvenir Part II" has been one of the clear standouts at the Cannes Film Festival. It played in the Directors' Fortnight, which runs parallel to the Cannes official selection. It's a hushed, formally composed film that played down the Croisette from Cannes' central Palais. 

Still, few movies here have spawned as much fawning over. Hogg's project has already attracted a wide array of admirers (Martin Scorsese is an executive producer of both films). But "The Souvenir Part II," which a24 will release, only enhances Hogg's achievement. 

Honor Swinton Byrne, left, and Tilda Swinton pose for photographers at the photo call for the film The Souvenir- Part II at the 74th international film festival, Cannes, southern France, Thursday, July 8, 2021. (Photo by Vianney Le Caer/Invision/AP)

"I've rediscovered a way of making films that I enjoyed when I was at film school before I got sucked into television," says the 61-year-old Hogg, who didn't make her feature directorial debut until 2007's "Unrelated." "It was the making of the film within the film within the film — I don't know how many inside boxes there are."

The hall-of-mirrors nature of "The Souvenir" only gets weirder. Tilda Swinton, an old friend of the director's, starred in Hogg's original 1986 short film, titled "Caprice." In "The Souvenir Part II," Byrne wears some of her mother's clothes from that time. After the first Cannes screening of the film, Swinton said emphatically, "It was a trip." 

Hogg acknowledges that even for her the lines between memory and fiction have blurred. Toward the end of "Part II," Julie is interviewed about her student film — a scene that Hogg feels being replayed for herself. 

"I almost feel like I'm inside a film as I'm talking to you," Hogg says, laughing. "We have Julia being interviewed, and she's saying exact words that I said in an interview in the late '80s. It's too weird. Maybe I'm dreaming. Maybe this is a film."

But if there's so much still unclear for Hogg about her experience completing "The Souvenir," what's absolutely uncomplicated is that, 35 years later, she's fully realized herself as a filmmaker. 

"I feel more emboldened," says Hogg. "I seem on the surface to be quite reserved and a bit shy — that's how I feel, anyway. But when it comes to making my work, I'm like a dog with a bone. It's my lifeblood."