Another snippet from Responsive Day Out. This one from Jeremy Keith:

Responsive web design is an admission by our industry that we never had any control over our clients or their audience. What is control anyway? We have no control over what device they use to access the web or their capabilities.

As web designers we make assumptions about how people use websites. To us scrolling, clicking, pinching and zooming are second nature. To none web designers these things may to be that obvious. Not everyone knows the logo on a website is often the home button (ask you grandma if she knows).