Hypnosis could work if you're susceptible to it. I don't think I would fool myself with the "wait a year or more" thing. Unless said person was really competent, and said "What the hell kind of request is that? You need professional help." (or something to the same effect, but more plausible and less exaggerated) when you asked, and then did it anyway a few years later.

I don't know anyone with the skills to do either plan who I think would be willing to entertain weird requests like that. Also I wouldn't like to make my reaction known to other people without knowing it myself first, because I might not be sad enough for their expectations. Especially the expectations of the person I'm supposed to think has died.