Dame Helen Mirren learnt to smile in her "mid-thirties".
Dame Helen Mirren
The 71-year-old movie legend avoided grinning at people for over three-decades because she thought she looked "stupid" when the corners of her mouth turned upwards, but after she urged herself to grin more she noticed it instantly made her feel "a little bit better".
Speaking about her difficulty with the expression on 'Victoria Derbyshire' on Thursday (23.02.17), the 'The Queen' actress said: "It was only actually in my mid-thirties that I learnt to smile. I couldn't smile before that, I thought I looked stupid when I smiled.
"And then I learnt the power of a smile and funnily enough when you smile, even if you don't feel like smiling, you immediately feel a bit better.
"Life feels a little bit better when you're smiling."
However, Helen has admitted she has battled with her lack of self-esteem throughout her life, and she still struggles to feel positive on a "daily basis", a trait she believes "everybody else" suffers with.
She explained: "I don't know if anyone else is different than me but it's something I have to handle on almost a daily basis.
"But certainly it's something I am aware of on a daily basis, you know, self-questioning.
"Certainly, it's more exacerbated I think when you're younger because you don't quite know what your place in the world is going to be.
"But I think those moments of self-esteem certainly don't go away as far as I'm concerned, you know, into your adulthood.
"The only comfort I find is I think everybody else is like that as well."
But Helen believes her lack of confidence led her to pursue a career in the entertainment industry.
She said: "It may be one of the reasons I became an actress."