I think I was a bit of a DYKWIA a few weeks back! Boarding the A380 to Vancouver from LHR T3 the "fast track queue" was ridiculous, must have had at least 200 people in it and was an absolute mess.

So...I ambled up to the closest BA staff member, asked if this was fast track, which she confirmed yes. Then showed her my boarding pass and got an actual fast track.

Is this DYWKIA? Probably, but what would you have done...