[Pansy-Mae]

I do understand your point and in a perfect world I would 100% agree. However the point is that in this world you can't even begin to predict the final outcome,

If that were true, then I guess that that would make most of the people on this
forum a bunch of idiots. Because, let's face it, many come here looking for advice,
recommendations, discussions and so on. If NBE were absolutely unpredictable,
we would have nothing to talk about. Naturally, there exists a (vague) line
that separates that which can be reasonably accurately predicted from that
which can't.

To get back to my original question... I'm interested to know whether
anyone experienced growth exclusively on one side. I do realize that
the two sides may not (and probably will not) grow at the same rate,
but is it possible for one side to not grow at all?

OK, on that basis and by your definition, that does indeed make most of the members of this a site a bunch of idiots.
I say again, NOBODY can predict the outcome and that is exactly the reason why there is discussion, debate, sharing of experiences, swapping from one programme to another, trying to find something that works for one specific individual. As we've all said many times over, everyone is different and reacts differently to different things and that alone tells you that the outcome is unpredictable!

To answer your second point, like sfem, I've never heard of an adult woman with only one breast but since I have heard of at least one poor woman who grew three, I suppose in theory it is possible.
You might want to try googling the question... I did, and came up with this for starters:
http://life.familyeducation.com/puberty/growth-and-development/42265.html