Because I'm an impatient brat who never does as I'm told. And I've always played games on the premise that you can't do anything in mist games that means ultimate failure as in...
Spoiler!
if Arno says I guess I'll wait here then and I quickly get bored and start wandering around and find the next thing to do then I figure either I won't be able to do anything until I've waited for whatever needs to happen as the game won't let me or I'll do something more interesting fir a while even if I end up going back to complete the first bit....