[He watches her reaction, expressionless-- then he leans forward, tone imperturbably calm.]

Time is a tricky thing, Katara.

I've spent an hour on a boat before-- only to return to shore and find that three months had passed since I set foot there. And this world is nothing if not strange.

Everyone I've ever spoken to who has returned home before being caught here again has said the same thing: they returned as if no time has passed. [a pause, and then, bluntly] Aang isn't alone. The one who has to do the waiting is you.