This was about 9 years ago, when I first started working, so LAA.

One early morning I had a flight out of DFW. I bleary eyed made my way to the gate, scanned my BP, boarded the plane, the FA hung my jacket and served me a coffee. All is well until the pilot comes on and welcomes everyone to the flight, said they're done boarding and doing some pre flight checks and we'd be off to Minneapolis -St Paul.

I was supposed to be headed to Detroit.

Somehow boarded gate A18 instead of A19 (or vice versa) #dumbass.