 The proposal that it is not you yourself but similar “counterparts” to you, who are relevant in this way to what you yourself might have done, is unappealing at face value: intuitively, as Noonan says, a claim about what you opted not to do but certainly “might have done hardly seems, at first sight, to be correctly interpretable as a claim about what someone else (however similar…) does in another possible world” (§6 of the entry on  identity:  this is a cleaned-up version of the so-called “Humphrey objection”: Kripke 1980, p. 45n.13; 1971, p. 148; cf. Lewis’ replies to the Humphrey objection as originally cast: Lewis 1986, p. 196).