Any number of reasons. I don't know a damn thing about Second Magic past what I just told you; therefore I have no idea if time truly operates on the same scale. Especially somewhere like this, which as far as I can tell might as well be another metaphorical tree entirely.

...But mostly because if I'm wrong and I've already been missing for this long, every single person I know is going to kill me either metaphorically or literally when I get back, and that's not a thought I want to contend with.