I would never mug myself, for three reasons.
Firstly, petty crime makes me very angry, and as such I've gone over what I'd (like to) do in those situations countless times.
Secondly, because I have no money, and I'm quite strong. I'm a terrible target.
And thirdly, because I've often fantasized about clones of myself, so any alternate me would absolutely seize that chance.
I was going to suggest that if what the OP says happened did happen, for whatever reason, that I would attempt to explain the situation... baring in mind that the money is just going to myself, but again... no money. I'd have better luck asking or taking from elsewhom. Which is totally a word.