See Which Costar Hugh Grant Calls 'Not Remotely Sane' - and Which One 'Wanted to Kill Me'

When it comes to discussing his former costars, Hugh Grant is not only honest but also hilarious.

The Paddington 2 star, 57, describes Emma Thompson, his Sense and Sensibility and Love Actually costar, as “a genius” but quips that she is “not remotely sane. She’s nuttier and nuttier as the years go.”

Grant says his Florence Foster Jenkins costar, Meryl Streep is also “a genius” — but a little challenged in the eyesight department.

“She doesn’t see very well, but she refuses to wear contact lenses. The result is, if we’re doing a scene, I could have been Denzel Washington,” he tells PEOPLE’s editor in chief Jess Cagle in the latest episode of The Jess Cagle Interview.

But when it comes to Robert Downey Jr., whom he worked with on the 1995 drama Restoration, Grant says he did not receive a warm welcome.

“He hated me. He took one look at me and wanted to kill me,” says Grant, who also talks about his rise to fame, his most famous roles and his life as a father of four (with a fifth on the way) in the interview.

For more from Hugh Grant pick up the latest issue of PEOPLE, on newsstands Friday.

Luckily this was not the case with his Bridget Jones costar Renée Zellweger.

“Renee loves me and I love Renee. Well, I mean she’s in the same category as Emma Thompson, in terms of lunacy, but an amazing actress of course, and very generous,” he says. “She once sent me a fabulous huge volume of beautiful photography, including a lot of semi-undressed women. I remember it because I had just landed in Marrakesh … and the book was impounded.”

Paddington 2 hits theaters Jan. 12.