With pain in general, a primary injury will cause you to be less focused on, or even forget about a secondary injury.
When my heart hurts for someone else's struggle, my pain is less.
Though outwardly we are wasting away, yet inwardly we are being renewed day by day. For our light and momentary troubles are achieving for us an eternal glory that far outweights them all. So we fix our eyes not on what is seen, but on what is unseen. For what is seen is temporary, but what is unseen is eternal.
2 Corinthians 4:16 - 18
For just as the sufferings of Christ flow over into our lives, so also the comfort of Christ overflows.
2 Corinthians 1:5