I say: "I can probably handle my own generally - got in a few scraps as a teenager so I know what I'm doing. Obviously more that one person might be trouble."
Reality: "I will get in a maximum of one punch, and if it's not a good one, I lose all momentum and am probably going to get severely hurt. In this situation, I will try for a sneaky kick to the knee and run like merry hell, which fortunately I am quite fast at. If there is more than one person it'll pretty much be a gangrape."