"We should have won it by now," said Cole. "That's what I believe.
"There's no point splitting hairs over things that have happened in the past but the semi-final against Monaco was particularly disappointing - especially the away leg.
"We got beaten by a side we should have overcome. Then you've got the Liverpool game the following season where we were let down by a dubious goal.
"But, as I said, you can't split hairs about this kind of thing. It's all in the past. I believe we've had a final place taken off us on three occasions.
"But the margins between winning and losing at this level are minimal and we really need to focus on how we perform in each game.
"The way I see it, the Champions League is work in progress at Chelsea. We haven't won it but our record over the last four years stands up against that of any club in Europe in terms of consistency and getting within spitting distance of the final.
"But no-one remembers semi-finalists or losing finalists. They won't remember dodgy goals at Anfield or bad decisions in Monaco."