Meanwhile, the present alone is ours, and we let it slip through our fingers. The past is gone, whether for evil or for good, to be stored up in better hands than ours. The future still belongs to God alone; and it is not the least of His wonderful mercies that He keeps it entirely to Himself. It is what I am now, not what I have been or shall be, it is what I do now, not what I have done or shall do, that here and now matters most, to me, to God and to all the world besides.
Those who face what is actually before them, unburdened by the past, undistracted by the future, are they who live, who make the best use of their lives. These are those who have found the secret of contentment. For such, there is no day that cannot be lived through, no matter what it may bring. There is no circumstance that cannot be put to the best advantage, no matter how contrary and galling.
~ from Spiritual Excellence by Alban Goodier