I would say this is not at all fact but instead only anecdotal as the only real difference from bottle to bottle you should taste if age and setting (comment about glasses is right on the money) is when a particular bottle is bad. Terroir and the discerning of its characteristics relies heavily on similarity.
Sorry, I wasn't clear with what I was trying to say - the wine might be exactly the same but my perception of it might differ dramatically from one day to the next. Don't know if that's normal or not, but definitely happens for me.