It´s guaranteed to lack again. And it starts almost immediatly after the incident. The only question is how long it takes to lack enough for the next time. The length of the period usually depends on the amount of your practice. In the case of the lumberjacks the instructor said that this period has a three year average.
I found an advice for coping with the decreasing care in a book about motorcycling. The author recommends to use a tally and increase the count each time you make a mistake. I tried it and it actually worked for me.