That doesn't explain why we should be surprised about a personal friend winning the lottery, though. That seems to be surprising solely because of astronomically low odds and the specialness of the outcome.

And the outcome is special only because the set of people categorized as "personal friend" is determined before the lottery winner is announced.

If you draw a card at random from a shuffled deck, whatever card you get had a 1/52 chance of being selected; this is only surprising if you predicted in advance that it would be that specific card.

Far trickier is how to determine "surprisingness" in cases where the space of possible outcomes is partially or completely unknown.