Barry Ferguson decided to rejoin Rangers from Blackburn after realising a Lancashire derby with Bolton paled against an Old Firm game.
"There were 27,038 at the Reebok and I have to be brutally honest. That's when I looked round and Rangers really started tugging," said Ferguson.
"I respected what that game meant to Blackburn fans but I knew then that Bolton-Blackburn just wasn't my place.
"I was brought up dreaming of representing Rangers against Celtic."
Ferguson joined Rangers on the final day of the January transfer window for £4.5m, 17 months after he left Ibrox in a £7.5m move south.
As the Scottish international prepares for Sunday's Old Firm derby, he admitted he could not motivate himself in the same way for Blackburn's Lancashire encounter with Bolton.
Ferguson said: "They told me at Blackburn that this was it, this was the game that meant everything.
"Bolton Wanderers at the Reebok Stadium on 28 December, this was the derby Rovers wanted to win more than any other game.
"On Sunday I'll be in the middle of one of the biggest games in the world - I don't think you can argue with that."