The 2009/10 champions kicked off their title defence in magnificent style with a host of scintillating performances before things badly fell away.
However, the Blues fought back to pose a serious threat to eventual champions Manchester United and the mettle shown by the Stamford Bridge players was not lose on England left-back Cole.
"At the start of the season we played some good football, some sexy football to be fair," he added. "Blackpool at home in that first half was special, but it's been a tough season.
"When we had that crazy, not even a blip, an unheard of period for any team, everyone wrote us off and rightly so.
"But give us credit for coming back and it's an achievement to come second in the Premier League.
"That said, though, we feel as though we should be winning and we want to win, but second is not bad in this league."