4. Border Control Will Not be Happy
I can only imagine the problems that arise from losing your passport and the panic of having to deal with it at such a young age. There are probably at least a few safeguards in place for circumstances like this for someone, and it is a shame the OP did not elaborate on how the rest of the story panned out.
On an unrelated note, can we also just give some kudos to the flight attendant who was actively trying to be helpful and fix such an unpleasant situation? It’s easy to forget how many terrible experiences flight attendants have to put up with, considering they are basically the only ones really responsible when the plane is in the air.