Well, insofar as the doppelganger and I have sepata experiences, our personalities have already begun to diverge. Now, if the doppelganger whipped out a pair of EEG helmets and demonstrated that we could sync our experiences - eg, I take a sleeping pill and let my doppelganger go out on the town for a night, but I can easily 'catch up' the following morning - then i'd think about it.
