That's because at the beginning of his career while still at school, he used a technique he picked up from acting guide Teach Yourself Film Acting that told him never to blink.
The 88-year-old told The Mirror: "One thing that stuck in my mind was, 'Don't blink. You must never blink'.
"For the next eight years, I walked around trying not to blink. People around me, my mother and everybody, thought I had gone nuts.
"They thought I was a psychopath. I used to frighten the life out of people."
Caine's commitment to trying to keep his eyes open at all times even led to him getting the school nickname 'Snake Eyes'.
He's far from alone in terms of actors who use the no blinking technique. Sir Anthony Hopkins also used the trick when playing Hannibal Lecter in The Silence of the Lambs.
Hopkins has previously said: "If you don't blink, you know you can keep the audience mesmerised. It's not so much not blinking, it's just being still. Stillness has an economy and a power about it."
As for Caine, we all know how his career has gone. One of only four male actors to receive Academy nominations across five decades, he has appeared in some of the all-time classics such as The Italian Job, Alfie, Dressed To Kill, Educating Rita and Hannah And Her Sisters.
However, it was one of his later era films that he rated as 'one of the greatest things I have done in my life'.
Caine famously played the role of Bruce Wayne's butler Alfred Pennyworth in Christopher Nolan's trilogy of Batman films between 2005 and 2012.
Despite initial scepticism over the role, he revealed it's a time he looks back on incredibly fondly.
He said: "He [Nolan] came to the front door of my house in the country with a script. I could see him through the glass but I couldn't recognise him. The moment he introduced himself, I knew exactly who he was because I was a great fan of his three small films.
"I told him, 'I am too old for Batman. Do you want me to play the butler? What would my dialogues be? Would you like another beverage or more custard?'."
Nolan won over Caine though, explaining that he saw the character of Alfred Pennyworth as much more than just a butler - more the 'the foster-father of Batman'.
The rest, as they say, is history.
Caine said: "So, I did the movie and it was one of the greatest things I have done in my life."