What doth care about future events bring thee, save sorrow upon sorrow? Sufficient for the day is the evil thereof. It is vain and useless to be disturbed or lifted up about future things which perhaps will never come.
It is not things that disturb us, but our judgments about things. For example, death is nothing terrible, for if it were, it would have appeared so to Socrates; but the judgment that death is terrible — that is the terrible thing.
What I urge is that you so learn to control the machinery as to live with 'day-tight compartments' as the most certain way to ensure safety on the voyage. Touch a button and hear, at every level of your life, the iron doors shutting out the dead yesterdays and the unborn to-morrows.