Why do people always say: I am not like other (women/men)?

I said to a younger woman recently I would love to buy her flowers. Her response was that she was not like other women, and wasn’t that interested.

We did continue to talk about flowers; she has a particular favorite and discussed how sad it was that they do not last. Clearly she likes to receive flowers.

Many women have said to me “I am not like other women…” when I have said something that seemed to be gender typing. Why do they do this? Is it to avoid giving credence to a gender stereotype?

Men feel free to answer if you have said “I am not like other men.”