[He's starting to suspect some sort of timeline difference. The event in question raises some suspicions he doesn't want to face. So he explains slowly and calmly.]

Well... I remember that me and Katara were outnumbered by Azula, Zuko and the Dai Li. As a last resort, I... [gave her up] opened my last chakra to enter the Avatar State, because I was afraid of what could happen to Katara. But Azula took me by surprise and... she got me with lightning right after I entered it. [His face sours and he turns away for a moment at reliving the memory.]

I... I was a goner. I could feel the Avatar cycle slipping away, but... Katara brought me back. I woke up long enough to see her happy, after she was able to heal me with that spirit water. And then, after that... I didn't really wake up for weeks. [A bright smile] So long I grew hair!