The whole mess reminds me of that form my wife had to fill out when she was teaching music in school, asking if she'd ever used marijuana. The administrator told her to just write no, if the answer was yes, one time at a party when I was 19. Millions of teachers and subs lie on that question because the whole awful machinery lurches into CRUSH mode if you are honest. Basically the school system has to assume that "once, decades ago," is untrue and that the respondents are likely dope fiends.
I suspect that millions of people similarly lie when answering the question on a firearm purchase form.