Talk:Epic Rap Battles of History 24/@comment-124.171.25.1-20121023223125/@comment-60.241.26.65-20121025094336

Actually, timelords can only regenerate 12 times.

However, on November 13th 1955, Doc Brown wakes to Howdy Doody and recollects the events of the lightning strike. Marty proves to him that he's from the future by showing him a letter sent to him by Doc.

That's my theory.