Deleting memories

Eternal Sunshine of the Spotless Mind was on Channel 4 last night. It's a great film, but I'm not going to review it. The film (rightly for the story it is telling) ignores a lot of practical issues in deleting the memory of a relationship, but it does leave me thinking... What would it take to actually delete a relationship from someone's memory and not have them figure it out afterwards? I'm going to assume for the point of this discussion that the technology exists to selectively delete memories, and no amount of hypnosis, surgery or other therapy could restore them. What else would need to happen to effectively delete the relationship? In the film, family and friends were given cards saying "Don't mention this relationship to the person", and a well meaning friend told Joel why Clementine couldn't remember him. With the best intentions, this method isn't likely to succeed (just as it didn't on film), so for the purposes of our thought experiment the memories of all your friends and family would also need to be modified, along with their friends and families to whom your relationship was mentioned. Then comes the practical stuff. What if the couple lived together and you found yourself either homeless or paying mortgage/rent you can't afford on your wage? Joint bank accounts would have to be deleted, along with anything else set up in joint names. Any writing or photographs showing you both would need to be destroyed, etc. I imagine junk mail in the name of your ex would be OK though as it would be simply ignored or returned to sender. The magnitude of changes that would need to be made just becomes greater and greater the longer the relationship had gone on. I imagine deleting a single one night stand wouldn't cause too many problems, but deleting a long term close relationship would be a lot harder. If you'd been married for years you could end up modifying the memory of thousands of people. This leads us to another thought. What state would you be in after the operation? Would your personality revert to it's state before you met your ex, or would you have all the psychological changes it would have caused (but without the concrete memories to back them up?). My instincts tell me this would lead to great depression. Human memory is fairly fuzzy, so how would your mind fill in the time gaps? I doubt many people can remember what they have had for dinner every day for a month, but there would be a lot of significant events you would have to cover for. Anyway, this has been a pretty rambling post, but it's an interesting thought. Incidentally, this is my 50th blog post!