Confluence is not a co-incidence. Rather, it can never be. There is a certain amount of overlap in the intent so that confluence happens and more so, gets noticed.
There's only a hairline's difference between describing confluence in a proletariat-like manner and noticing that there might be just a little more. What that is, no one cares. Or maybe no one cares to find out beyond a certain extent, never discounting the fact that the intent is always alive.
What then separates confleunce from co-incidence? Conflueuce is rather more mutually driven and borne out of some attraction of thoughts. Co-incidence does not have a history. It has no evidence of an intent in the background of its existence. In fact in most cases, its born out of nonchalance.
Confluence reminds me of a situation in which 2 people are fooling each other. It's a sweet willingness mixed with a drop of reluctance and 2 spoons of confusion and the vision of the dish is rather blindfolded. After all there was no blindness, visual clutter might steal away the beauty of confluence, right?