Long-term thinking turns temporary setbacks into small data points.

The same setback can be a catastrophe or a data point depending entirely on the timescale you are holding. Over a week it dominates everything. Over a decade it is one of hundreds of similar events, most of which you will not remember, and it changes nothing about the direction.

When something goes wrong, deliberately zoom out before responding. Ask how this will look in three years. The event does not change and the appropriate response usually does.