Quantity spoils quality?

Tonight I was poured an Ardmore. My boss, who did the actual pouring made it a rather large one. At least to my standards. I'd had a dram from this bottle on a previous occasion and must say that I had enjoyed it very much then. But tonight the Ardmore seemed off.
At first I blamed the mood. You know, as there is a whisky for every mood, I apparently wasn't in the mood for this one. Then I thought it was the glass. No fine nosing glasses at work, so the Friday night dram was consumed in a Cognac glass. Yet the week before that same glass hadn't been a problem, and I should just remind myself to bring a proper glass on Fridays anyway.
On my way home, it struck me : the quantity.
You see, yesterday night I poured myself a Caol Ila, in the comfort of my own home, at ease, so the mood couldn't have been a problem, and the glass was just fine. Yet in my enthusiasm I accidentally poured somewhat more than I am used to. And it too didn't feel right. Now this can mean two things : I am either currently only in the mood for the most typical of Irish whiskies or it was the quantity that spoiled it.
How quantity can do that, I have no idea. Perhaps it is the ratio air to whisky in the glass that unbalances the right conditions for the aromas , or the fact that the greater amount of whisky makes you take bigger sips, allowing for the alcohol to numb and subdue your palate.
Perhaps I should just take more care in the size of my drams, and perhaps experiment with it.