At the end of his article “Meaning” Grice says roughly that interpreting a difficult text–say a philosophical one–written by oneself can be as much an act of decision as an act of remembering. Presumably this is because what you intended at the time, which for Grice is determinative of speaker meaning, may be lost to all. Interpretation is as much a case of making a reasonable choice for you as for anyone.
I imagine that one is trying to determine what one might have intended, given the timeless speaker meaning of the utterance–that is, the intentions you normally have when you use utterances of that type. Any information you had about the context in which you made the utterance would of course also be salient. What question was the utterance an answer to? What was the topic of the conversation.
A student wrote a paper for me late last term that argued that Grice’s theory of meaning was in direct conflict with Wittgenstein’s — or in any case Kripkenstein’s — views about the possibility of private language. But if interpreting yourself is just like interpreting others, it seems to me on the face of things that in fact the opposite must be true, albeit for reasons that have nothing to do with rule-following. If I have to interpret myself using the same standards I would to interpret others, then it seems like all languages are public in principle. And furthermore, Grice’s comments about self-interpretation seem to me to echo some of the things Wittgenstein has to say about determining whether I am myself in pain. No privileged first-person knowledge in either case.