So I am playing on long life span with mccc...one of my children is 3 days out of 52 and she just met a potential future mate I think would be great to play off as the geeky lovers who met as children...
I can't check in game but I'm sure there is a Potion of Youth reward trait under the aspirations section of your sim (the little present symbol). I think its about 1500 points and resets your sim's (the drinker of the potion's) current age. I don't think it resets any traits, looks, achievements etc. just winds the clock back to start the current the age again, but don't take my word on that.