Sir Derek Jacobi learned valuable lessons through Laurence Olivier's criticism.
The 84-year-old actor was a founding member of the Royal National Theatre in the UK, after being enlisted by the acting legend, who died in 1989, aged 82.
Derek told the Observer newspaper: "He saw me at the Birmingham Rep. The first job he gave me was playing Laertes to Peter O’Toole’s Hamlet, and I stayed with him for the next seven years."
Derek was actually reduced to tears by the award-winning actor during one rehearsal.
But Derek admits that he "needed" to be told some harsh truths at the time.
The actor - who has appeared in numerous Shakespearean stage productions during his career - shared: "I was taking over from Albert Finney, a big star. Olivier came to watch the rehearsal and was vitriolic to me. He hated what he saw and told me so.
"I was no Albert Finney and I needed to be told that."
Asked whether he received constructive criticism, Derek replied: "At the time, I thought no. I went away and cried. But of course it was. He wouldn’t destroy just for the sake of destroying. He was better than that. If he destroyed, he created at the same time."
Meanwhile, Derek believes that "the use of voice, the magic of voice, has all but disappeared [in the theatre]".
The acclaimed actor would love to see the return of "vocal expertise, to make the words more important than the sight".
He added: "One of the magic things in the theatre – the uniqueness of the theatre – is the sound. The voice that can fill an auditorium from the front row to the back of the gods is thrilling."