Okay, so this is exploity, and probably not allowed in true, honest and pure legacies; but I also figure a few other simmers might want to take advantage of this. It is a way to keep a sim immortal and thriving without needing to lure unsuspecting neighbors and/or homeless sims towards your cowplants. Immortality without the moral question marks, if you will. It does take work; both to set it up, and continuing to make friends when the need arises. Haven't seen anyone else posting it yet, which kinda surprises me a bit. So here goes...
Step one, get rich. Whatever means you choose. My sims did it honestly with painting.
Step two, knock out the Mansion Baron aspiration. After you have succeeded with it, keep everything you needed to meet it, like the windows, columns, artwork, value of the house etc.
Step three, make friends. Not just drinking buddies, but buddies that will move in with you if prompted.
Step four, invite a friend to move in with you when you need some youth potions.
Step five, change their aspiration to Mansion Baron. Whip! Zing! They have 4500 Satisfaction Points with which to reward you three Youth Potions for letting them crash on your couch. None of the goals to be met have any "activities" tied to them. Just stuff and real estate values gets the job done.
Step six, lather, rinse, repeat, move out as necessary to maintain both your youth and your sanity. In case anyone isn't aware, you can use the "Ask to Move In" friendly social option to actually move someone out of your house and into the friend's house. The active house after the transaction will be with the sim that did the asking, no matter what direction you are moving sims.
P.S. You have to be active on your home lot or the requirements won't trigger for the aspiration with the new sim.
