Everything new troubles us. Life catches us unawares and obliges us to journey towards the unknown, even when we do not want to, even when we do not need to.
Look not mournfully into the past, it comes not back again. Wisely improve the present, it is thine. Go forth to meet the shadowy future without fear and with a manly heart.
If you have fear of some pain or suffering, you should examine whether there is anything you can do about it. If you can, there is no need to worry about it; if you cannot do anything, then there is also no need to worry.
Terrorist attacks can shake the foundations of our biggest buildings, but they cannot touch the foundation of America. These acts shatter steel, but they cannot dent the steel of American resolve.