A couple of times. The most annoying was when my husband, older teenage daughter and I were travelling together from the Gold Coast back to Perth. Like a lot of teens our daughter was going through a stage of being too cool for her parents and wandered off once we checked in and were in the departure lounge. When the time to board arrived, we couldn't find her. We searched everywhere and announcements were even made over the speakers but to no avail...all three of us missed our flight (although she was 17, she was still legally a minor, so we couldn't leave her behind) and had to spend a lot of money purchasing another ticket. We found her shortly afterwards, reading up the back of one of the bookshops, so absorbed in a book that she hadn't even heard the announcements calling out her name. My husband and I were fuming!
Not so much anymore but we used to travel quite extensively by plane and we have never missed one. At least not that was our fault. We flew from Dallas to LA to catch our flight home to Oz and the Dallas flight was delayed. We had to spend another day in LA because they only flight out once a day. But it was 2am before the airline got us to a hotel. It was really stressful cause we also had a connecting flight in Australia and a bus ride before we could get home which had to be rescheduled as well.
No, never! Always arrive at Airport approx 90-120 minutes' prior Domestic & 3 hours' prior International flights.
I hate unpunctuality of any form, but I'm particularly aware of catching an aircraft on time.