Trying to Understand Girlfriend?

Been in a relationship with a girl for 3 months. It has been pretty much a fast relationship which has resulted in her moving in with me recently. Yesterday I decided to be really nice and went to the store and bought her flowers. I ended up having to go to a second store because the first one didn't have purple flowers. Purple is her favorite color and before she moved in I sent her purple roses which she seemed to like. She knew that I had to go to two stores to find what I thought she would like. When I brought them home she wasn't surprised at all and really didn't even seem interested. I trimmed off the ends and put them in a vase and put them on the counter. A couple of hours later I asked why she didn't like them. She then told me that she didn't like daisies. I was pretty surprised that she wasn't at all happy that her boyfriend tried to make her happy with a gift of flowers and discretely threw them away and after a while (after she didn't notice that they were gone) told her that I threw them away and apologized that I didn't get the right thing. She said "that's ok" and that concluded any discussion on the topic. I did something that I thought would be considered sweet and instead of any thanks or appreciation I walk away feeling like I did something wrong. Any thoughts from anyone?