Significant Accident (1)

I had my first really expensive accident in a game late last night, I was perhaps too tired to be playing anyway and don't really know whether I did anything too blonde. I have asked the "2 Plus 2" guys in this thread. Some of them clearly know what they're talking about although, as in other forums, the confident- and fluent-sounding ones by no means always agree! Still, it will be interesting to see whether they all tell me more or less the same thing. In that forum, they don't like you to give the result of the hand when requesting advice, so nobody can subconsciously be influenced by the outcome, so I didn't, but I can give it here: I went all in for the remainder of my $200 table-capital and was called by someone who had flopped a higher set than mine. He had pocket 9's, in other words, which I did not expect at all (though obviously I did ask myself, because that's the only possible hand that can beat mine at that point). I thought/hoped he had either AK or an overpair - maybe 10's or J's with which he had not himself originally raised, but had called a pre-flop raise, or even Aces which he had been slowplaying, as some people will). A setback indeed, though I am still a fraction ahead there overall ...