Plans have a way of going awry. Mishaps can occur when you least expect them. They can change your immediate or long term future, can be irritating, inconvenient and sometimes cost money.
Take advantage of these mishaps and don't let them go to waste by including them in some shape or form in your plotline.
That's not the only time I've used a mishap to advantage in one of my books.
At one time I suffered from dizzy spells, shaky hands, and sometimes double vision, which were symptoms of a bout with hypoglycemia, a/k/a low blood sugar. I decided to bequeath a form of this episode in my life to the main character, in my romantic suspense, Killer Career. I wanted her to suffer, wonder what was wrong, yet be able to get better.