Following the trauma of a shoe lace breaking on the start line during that final tightening, and having been a planner in a previous existence, I have tended to retain the laces of shoes after disposal in case of a similar emergency.
An audit has revealed I now have at least 25 spare pairs in all the hues associated with Walsh, INOV-8, Salomon etc over many years which prompts the question; "how many spare laces does a fell runner really need?"