The 67-year-old actress, who has played the Walford matriarch since 1986, confirmed that life on the BBC soap's set never gets boring due to the constant potential for twists and turns on screen.
St Clement told The People: "I don't get bored of playing Pat because I don't feel I am still playing the same character I was playing in 1986. The characters have to move on and evolve and that is what keeps it interesting.
"I wouldn't be comfortable coming to work in the morning if I felt I knew exactly where Pat would be going next."
The Albert Square legend added that she currently has no plans to quit the drama but would never take her place in Walford for granted.
She said: "I'm very happy with where [Pat] is. But I've learnt that nobody is indispensable on this show because the Square is bigger than all of us. I am very proud I have managed to hang around for so long. I take it as a sign that the audience has accepted Pat - blue eyeshadow, pink lipstick and all."