I have no idea how to operate a quick release, and had tightened mine until I couldn't clamp it, then backed off until I could just flip the thing completely in and secure. I thought that was pretty secure, throw the handle parallel to the fork and you're good.
Then I notice this loud sound like a few parts moving loose away from each other and slapping back together. The sound of a bunch of stuff bouncing in your rear basket, or whatnot. It came from up front!
Eventually (after 3 or 4 miles of confusion) I started intentionally jerking the front wheel up and bouncing it, causing the sound to repeat, verifying that yes this is coming from up front.
Stop the bike.
Looking, looking... quick release has been flipped back open.
Wait, what? That's physically impossible. It takes more force to open it than it does to keep it shut.
Oddly enough, the bike took a pretty severe beating with an unfastened quick release and it's fine. How it popped open in the first place is a mystery to me.