Originally posted by Sith Lord Windu
advent, you said that obi-wan gave into the darkside. i dont rekon he did, yeh he had a super pissed look on his face but i dont think he gave in. if he had, he would have turned to the darkside, as its been said its hard to turn your back on the darkside once you embrace it. futhermore, i think he simply focused all of his anger into his moves, allowing him to fight back... for a while.
Except that is incorrect. Obi-Wan Kenobi never actually joined the Darkside, nor fully immersed himself. There is much difference between using your anger in the way Kenobi did, and the supposed "quote" given by a fallible, third party character. Kenobi did give into the Darkside, he used his emotions in anger.
Furthermore:
"Kenobi, enraged, attacked Maul. This barrage was deflected by Maul who used Obi-Wan's touching of the dark side as a conduit for a Force attack; using the Force, Maul pushed Obi-Wan into a deep mining pit. Kenobi held onto an outcropping for dear life. Calming himself by calling upon the light side of the Force, Kenobi was able to surprise Maul, and cleave him in half with his saber. "
-- Star Wars databank, Darth Maul.
And the novelization more than backs up that he literally went crazy, and was attacking in a frenzy. Much like Anakin did in ROTS against Kenobi, not like Anakin did against Dooku. As well, Subjekt's analogy was perfect. Luke used the Darkside to fuel him in the duel against Vader (once Vader talked about Leia), once he beat Vader though, he calmed himself. Same thing.