As mentioned during the review of the fifth Die Hard film, A Good Day to Die Hard, Simon admitted that the phrase "to try hard" was something that had evolved in his family over his offspring's childhood years with regard to enquiring if, before embarking on a long road trip, they had been to the toilet and (especially) if they had emptied their bowels before the journey began.
For example: "Have you been to the toilet?" "Yes, Daddy." "Did you try hard?"
It was later suggested that this would make an interesting title to future films in the Bruce Willis franchise, along with retitling the second film to "Try Hard 2: Try Harder".