A BBQ party, with AK and other good people. At the end, I was in charge of the fire-extinguishing job. I stepping on the burning ashes, and got a remark from AF: "hey Pavel, what a self-sacrifice.." then he corrected himself - "..sacrifice of the shoe"
This is a story of a great coincidence. Later that night I was reading "mostly harmless". Well, guess any more words are useless - either you are already laughing or I don't want to spoil it.
Ford Prefect rescued himself "by means of self-sacrifice". In that case, he threw half of the pair of shoes (which maks one shoe) while hanging on a weather baloon - to divert a vogon rocket that was fired at him.
When asked how does it make a self-sacrifice, he replied 'Because they were mine!'. In this new terminology - a regular, plain sacrifice is when you sacrifice something that belongs to someone else. Quoting King of the far far away from Shrek: 'Some of You Will Die, that's a Sacrifice I'm Willing to Make'