I'm hard of hearing and terrified of standing in the wrong place at an airport and missing the visual cues to board the flight. Once boarding starts and people start queueing up, I usually get in line because it's helpful to see what everyone in front of me is doing - the order that they hand over paperwork or get carry on double checked. I can't guarantee I'll be able to hear the attendant if they ask me questions at the gate because it's so noisy, so I like to at least feel like I'm prepared.
One time I was flying with crutches and qualified for early pre-boarding because I needed the plane wheelchair (skychair). I sat right next to the gate desk and waited, then I started seeing people queue up so I quickly joined the line, wondering how pre-boarding works when the whole plane of passengers are already vying to be at the front of the line.
I get to the front, the attendant looks at my ticket then after some awkward back and forward eventually I realised they were telling me I'll have to wait till everyone has boarded to get the sky-chair on. I should have come to the desk when pre boarding was announced. I pointed that I was sitting right in front of them... Apparently they were called my name 3 times over the loudspeaker.
Apparently airports can only comprehend one disability at a time (if that!) they knew I was hard of hearing (it's on my ticket) but still thought calling me over the PA was the best way to get the attention of the deaf person sitting 80cm from their desk.
So I sat back down and waited for the line to clear, then I got back up when there were 2 people in line, and after another back and forward I learned that they had tried calling my name again about halfway through boarding because they only had one skychair and it was now or never because the chair had told fly with the other passenger because their arrival airport didn't have a chair, or something, I dunno, anyway I kind of had to crawl down the ailse to get to my chair because in the past I've just used the backs of chairs to swing myself along, but the plane was full so I couldn't do that.