Dev Patel thinks Maggie Smith put him to "shame" on the set of 'The Second Best Exotic Marigold Hotel'.
The actor - who continues his role as hotel owner Sonny Kapoor in the movie - felt as though the legendary actress, who stars as the hotel's co-manager Muriel, had so much more stamina than him.
He gushed: "She would cringe if she knew I said this but she is one of the most gracious, talented and incredible humans I've ever got to share the screen with.
"I mean I'm just astounded by her talent and her patience. We're in the scorching heat of India filming, our set is two hours away from where we're staying and we're traveling through these big, bumpy roads...
"She's got a great sense of humour and I was just astounded by her consistency take after take and just the stamina she has. (She) put me to shame really."
The 24-year-old actor also admitted he had to act like a "kid with Tourette's" to keep his energy going throughout filming.
He added to HitFix.com: "We get to set and it's long days and lots of scenes. And I'm kind of like a kid with Tourette's.
"Just to keep the energy [up] and the spontaneousness of this comedic character I'm playing and she's just so patient and lovely with me."