Kenobi aged a ton between Star Wars Revenge of the Sith and A New Hope.
Once he defeated Anakin Skywalker on Mustafar, he went into hiding at the orders of Yoda, on Tatooine, and protected Luke Skywalker until the time was right. These 20 years aged the man incredibly. Why was this?
The Plagueis novel has some insight as to this actually being confirmed, as well information giving credence to a Theory that I now have, regarding this matter.
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