It's always nice to be flexible and try to get along with people, but today you should stick to your guns about what you want to do. Don't let others hijack your sense of what is right and what is wrong and don't be afraid to disagree with people. If you become less wishy-washy, you will send a very clear signal to other people that you are not to be underestimated. Pushing your own agenda is not only a perfectly valid thing to do, it's recommended.