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.
The secret of health for both mind and body is not to mourn for the past, nor to worry about the future, but to live the present moment wisely and earnestly.
The future influences the present just as much as the past.
Never look back unless you are planning to go that way.
Unfortunately, the clock is ticking, the hours are going by. The past increases, the future recedes. Possibilities decreasing, regrets mounting.
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 
The secret of health for both mind and body is not to mourn for the past, nor to worry about the future, but to live the present moment wisely and earnestly.
The present is never the mark of our designs. We use both past and present as our means and instruments, but the future only as our object and aim.