I'm happy my post set the stage for such a nice conversation and really appreciate your replies guys (and gals). Lots of interesting stuff been said, some of which deserve a whole new thread to be discussed in depth. However, to get back to my original question: Seems like it's happened to others too (finding again someone from a PL in a different role) and I'd be very surprised if it didn't. What interests me more is, how people handle it. Seems that the best path is to keep it just for you, which is what I trust is the safest also - what good can come out of telling your wife that you can't touch her again a certain way because she was your son "that other time"? A free ticket to a mental institution maybe
But how do you cope with it? Let's say you never tell your wife from the example above, do you still treat her like you used to? Do you go on and pretend or manage to completely convince yourself that "in this lifetime, this life matters the most" - don't get me wrong, I do believe that statement and in fact I've repeated it more than once in this forum myself. But really now, say you're a man in this life and the love of your (past) life where you also were a man is now your sister - and they also look so much alike. Can you really, really function normally? Won't you have to adjust your life to this knowledge - say, avoid contact and interactions with her as much as possible?
I consider souls genderless and believe that it doesn't really matter because in a soul level the brief ("on-stage" performances of) physical lives are just acts, don't weigh for anything when you get to "meet again up there". Just like in a movie, when the act is over, actors don't take it personally when someone harms them inline with the movie script. It
does matter though during the movie - or the next episode of a series, as this reincarnation business seems to be.
There is a story about a guy who, while his wife is pregnant, has a dream. His daughter-to-be comes in it and asks him to call her a specific name when she's born. He does. As she grows up the two of them have this special father-daughter love in an extreme level, they like the same things (from colors to food to music to fav animal), they want to spend every hour of the day together, they play and laugh together, care immensely for each other. She asks him all the time if he loves her more than anything in the world. He at some point gets the extremely burdensome gift of remembering a PL in the US of A and one night he has this dream where his daughter is a grown-up girl when he meets her in that PL for the first time and it's love at first sight. He knows better than to believe that this dream is a PL flashback and is completely certain that, despite having absolutely no "sexual desire" for his daughter, his subconscious plays Oedipus Complex games - which is absolutely normal.
Then one fine day his 8yo daughter who doesn't speak a word in English tells him out of the blue the words "Remember me". In English. They just stare at each other in the eye and she repeats, clearly "Remember me" and leaves the room.
Could be a pretty good movie if done right.