I'll bite. Back when AA still flew out of OAK, I once accidentally showed up at SFO instead, because I didn't remember that I had booked the ticket out of OAK (since I usually just flew out of whichever airport was cheaper, which had been SFO the previous few times). There wasn't enough time to physically get to OAK in time (although that's what they originally told me to try anyway, and hope for a delay), but I ended up flying standby out of SFO instead.