Shaking someone's beliefs only makes those beliefs stronger (euraeka.com)

Unless you present them an alternative that works for them just as well. E.g. showing them GMail when they think Hotmail is the best thing ever.

Has a lot to do with keeping on keeping on with a startup as well. Too hard to just cave in to another reality where the company is not what is haussed up to be. To be able to fight for a reality at odds with the world is both a curse and a blessing.