TORONTO -- Dustin Hoffman turned 75 last month. Just don't tell him that.

"I'm shocked," the affable two-time Oscar winner said in an interview in a hotel room Sunday, while promoting his directorial debut "Quartet" at the Toronto International Film Festival.

"I've seen a couple reviews on this (movie), and it says: 'Hoffman, 75.' And I say, 'What? Who is that?' I see that 75 in print and I (think), 'Who are they talking about?'

"Sometimes when you (use) the iPhone, you want to take a picture of something and it's reversed and you (get) yourself instead. I see this old face and I say ... 'Who is that old (fart)?"' he added, in fact using a different four-letter F-word.

"That's me. And it shocks me! Because I don't feel that way. It's a stunning feeling."

The energetic, talkative Hoffman certainly didn't show his age during a whirlwind press session for his star-studded film, a comedy about an old-age home for retired opera singers and classical musicians.

The breezy but sharply observed film features turns from some of Britain's most celebrated actors, including Maggie Smith, Tom Courtenay, Pauline Collins and wild-eyed Scottish comedian Billy Connolly, who puts in a scene-stealing performance as the home's lusty, boisterous class clown.

Hoffman says he's long appreciated opera (he was introduced to it through Robert Duvall's brother when the two actors were roommates early in their careers), and in case there was any doubt, his singing voice could be heard ringing through the hotel hallways while journalists waited for their scheduled chats.

He was mischievous in other ways too. When an interviewer's phone began ringing while he was mid-sentence, Hoffman answered and pretended to give the photographer on the other line hell, shouting: "Get me those photos! You were supposed to get me the photos!"

Before that same interviewer left the room, Hoffman insisted on telling a funny, and very dirty, joke.

"I'm an immature person," Hoffman said, with nods of approval coming from his nearby staff.

"The only way I can get on is keep being myself. I've never grown up. Everyone who knows me dearly will tell you that."