The 33-year-old Blues legend said he thought he would finish his career at Stamford Bridge.
Arsenal's new goalkeeper Petr Cech, a phrase that may take some getting used to for many football followers, has written an open letter to Chelsea supporters on his Twitter account explaining why he has made the move to the Emirates, and thanking them for their support over the years.
In what must be one of the most astonishing transfers of recent memory, the Blues legend has moved across London to sign for Chelsea's fierce Premier League, almost certainly one of his old club's challengers next season.
As signings like this come around so rarely, the Czech international made sure he put together a message on what he claims has been an astonishing 11-year journey.
Here is his letter in full, as it appeared on Twitter:
Have Arsenal signed one of Chelsea's greatest ever players?
It would have been unheard of for the former Rennes man to be switching to a Premier League rival this time last year, and despite the significant rise of Thibaut Courtois as the best young goalkeeper in the world, many Blues fans are going to have problems coming to terms with Cech's switch.
This is a man who arrived at the very beginning of the Chelsea revolution in 2004, just a year after Roman Abramovich took over the club, when John Terry was still a young defender and the club had just one league title to their name.
It was the same season as Jose Mourinho arrived, and signified the time when everything wold change for the Blues.
In his time at Stamford Bridge, Cech has helped Chelsea quintuple the number of league championships they had, more than double their FA Cup haul, more than double their League Cups, and secure successive European trophies, including as Cech points out, the Champions League trophy in 2012, 'the biggest of all'.
When Chelsea fans in 50 years name their best ever goalkeeper, Cech is sure to be a frontrunner, they'll just be hoping Arsenal can't lay similar claims to the 33-year-old.