"She would have hated (my work)," the octogenarian German said of Gabrielle "Coco" Chanel, the French designer who started the label.
Chanel died in 1971 aged 87.
"Towards the end, she hated the miniskirts. And if you start being against the fashion of the time, you have a problem," he added.
"When I started at Chanel (in 1983), everyone said, 'Don't touch that, it's dead, it's finished!' and that's what amused me.
"It was like a challenge, and it worked, 100 times better than I thought it could."
Lagerfeld also said he had no plans to retire.
"I've not asked myself this question. And I'm still not in the bin," he said, adding that he had an "agreement for life" with Chanel.
The free exhibition, which runs until November 1, says it offers "a journey through the origins of Chanel's creations", capturing the "charismatic personality and irreverent spirit" of its founder and Lagerfeld, with several rooms showing their work.
The first evokes the places dear to Chanel: her home at 31 Rue Cambon and nearby Place Vendome in Paris; her boutique in Deauville on the north coast of France, and destinations that influenced her creations, such as Venice, England and Scotland.
A re-edition of Chanel's only collection of high jewellery, "Bijoux de Diamants", created in 1932, is among the items on show.
"It's a way for us to show the brand's creativity and to show the point at which this creativity allows the brand to uphold its development," Bruno Pavlovsky, Chanel's president of fashion, told AFP.
The exhibition includes a film showing an imaginary meeting between Chanel, played by Geraldine Chaplin, and Lagerfeld, whom she questions about his role at the fashion label.
"I am keeping you alive," he tells her.
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Chanel died in 1971 aged 87.
"Towards the end, she hated the miniskirts. And if you start being against the fashion of the time, you have a problem," he added.
"When I started at Chanel (in 1983), everyone said, 'Don't touch that, it's dead, it's finished!' and that's what amused me.
"It was like a challenge, and it worked, 100 times better than I thought it could."
Lagerfeld also said he had no plans to retire.
"I've not asked myself this question. And I'm still not in the bin," he said, adding that he had an "agreement for life" with Chanel.
The free exhibition, which runs until November 1, says it offers "a journey through the origins of Chanel's creations", capturing the "charismatic personality and irreverent spirit" of its founder and Lagerfeld, with several rooms showing their work.
The first evokes the places dear to Chanel: her home at 31 Rue Cambon and nearby Place Vendome in Paris; her boutique in Deauville on the north coast of France, and destinations that influenced her creations, such as Venice, England and Scotland.
A re-edition of Chanel's only collection of high jewellery, "Bijoux de Diamants", created in 1932, is among the items on show.
"It's a way for us to show the brand's creativity and to show the point at which this creativity allows the brand to uphold its development," Bruno Pavlovsky, Chanel's president of fashion, told AFP.
The exhibition includes a film showing an imaginary meeting between Chanel, played by Geraldine Chaplin, and Lagerfeld, whom she questions about his role at the fashion label.
"I am keeping you alive," he tells her.
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