I heard this on a Podcast several years ago now but it has always stuck with me.
The Best example of User Experience in Real Life.
A brilliant architect was designing the new front outdoor landscape of a university. When it came time to plan the walkways through the grass the architect refused to and instead opted for grass to be put EVERYWHERE. Not knowing his brilliance, the administration let the mad scientist have his way. A year later the architect came back to find a perfectly worn path where people walked and now they knew precisely where to put the path.
Moral of the story: don’t assume you know what people like, user testing is ten thousand times more reliable than “past experience”.
Don’t assume you know, assume others do and your job is to find out from them by observing and testing.