To approach the stranger is to invite the unexpected, release a new force, let the genie out of the bottle. It is to start a new train of events that is beyond your control.
... for those of us who lived through these events, the only marker we'll ever need is the tick of a clock at the 46th minute of the eighth hour of the 11th day.
The ideal reasoner, he remarked, would, when he had once been shown a single fact in all its bearings, deduce from it not only all the chain of events which led up to it but also all the results which would follow from it.