Quote Originally Posted by Galithar View Post
This is easy. Just write out your spellbook in advance. Then each level when your would get to 'add new spells to your spellbook' (I believe wizards get 2 per level, no?) You instead just say your abilities have regrown to the point you can use these spells again. Then your DM just drops new spells as normal and if it's not in your list your can add it per the normal methods. Who said an old dog can't learn new tricks?? :P
I think this is the best you'll get. Don't flavor your 2 spells per lvl as "researching something new", it is instead, having deciphered what you wrote almost a century ago, and regaining that knowledge.

For comparison, about a month ago I was checking some old 3.x builds I did, and I don't get half the things I wrote there. Back then I had all the books in my head, so just writing acronyms for feats, PrCs n items was more than enough. If I wanted to understand them now, I would have to sit a read for a while.