Oh, come now. All you have to do is, after every 100 years, smash yourself in the head hard enough so that you get Amnesia, then you re-learn everything. Repeat the process of giving yourself amnesia every 100 years, you'll do fine, and you'll even become BRAIN-DAMAGED! Hurrah! 8D

...

Really, perhaps it WAS a poor gift-- merely because Xande wasn't mentally able to handle it. He lacked the capacity to fully understand the shortcomings of immortality, and thus made his own life....something not worth living.

Hmm.
Don't you think Xande and Kuja are alike in many ways?