Those who are used to riding road bikes will know that anything but a smooth surface is the devil. Even a shallow pot hole can result in a flat. But you must remember that road bikes and mountain bikes are very different.
The mountain bike is designed to roll over tree roots and rocks and bounce down step sections. So trust the equipment and instead of attempting to swerve every obstacle (which is impossible on technical sections) trust that your bike will be able to deal with it.
