Yes, it's interesting how easily Keith accepts the idea that their meetings are fate! Perhaps the fact that there have already been three meetings by the time he hears of the prophecy makes that easier for him to accept, despite his general adherence to rationalism - plus of course things like that simply feel more believable when you hear them in the night in a smoky shieling lit by only a dim flickering light...

Plus of course if he accepts "fate" as the reason, perhaps it's a bit easier to remain in denial of his own feelings! Why worry about exactly what feelings are pushing him to act in a certain way when the real culprit is Fate?