Never received a citation for DUI but that isn't because I've never done it, I just got extremely lucky. I've driven UI a good 50 or 60 times, one of the benefits of living way out in the boonies and farm country where you drive through no heavily policed areas.
When I say "UI" I am referring to questionably being over the legal limit, not necessarily being fall-down sloppy drunk. Anywhere from impaired driving (lesser than intoxication) after having a couple drinks in a short amount of time to having several drinks + over a few hours. I was pulled over once and was probably legally intoxicated but the officer (a State Trooper) didn't even question it.
At the same time, there were many nights I didn't drive because I knew was just plain too drunk, the staggering kind of drunk. In my experience, most people have driven at least once when they shouldn't have, being legally intoxicated doesn't necessarily mean falling down drunk and swirving in front of on-coming traffic. Its extremely easy to pretend you're perfect on some anonymous internet forum vs. being in the company of people who know better.
For many people, the question is interpreted as "have you ever driven while you were drunk", implying the staggering, swearing, sloppy kind of drunk, and so they answer "no way, not me, I'd never do that", but if you ask them "have you ever driven a motor vehicle after having a few drinks" their answer changes markedly: "Oh sure...but I wasn't drunk."