That is so not what Tidus meant, and he realises he's stepped into a complicated story, more so than most people experience when Soldat answers him. Complicated. Complicated for him to even know what he thinks, but it's not something he wants to really pry into.

"'Don't worry about the past, live in the moment'? --That feels like something someone would say." And maybe it's his way, of not putting emphasis on the thought, on his original question. Maybe he shouldn't think as much either about his old, gone life. Sprinkled in with a little humour, to keep it light.