I don't think that amount/number is one of the things I shout at the TV about (such as less/fewer), but I am pedantic about my own usage of the terms. I think. I may have slipped on it, myself, on occasion -- I could see it happening in the case of one of those collections that is technically countable but not likely ever to be counted, such as the sand or the molecules.
On the other hand, "number of grains of sand" vs "amount of sand" are debatable constructions. If I were talking about the sand in my bathing suit, it would be an amount I was thinking of, rather than grains, although just thinking about it makes me feel every grain individually. If it blew into my house, I would say "look at all this sand", not "look at all those grains of sand".
I believe that I think of those in the same way as the "group rule", i.e. "the flock of birds is going south" because they are a collective even though they are multiple birds. The molecules, or grains of sand, are a collective unless you are specifically dealing with them individually.
And now Hex hates me.
On the other hand, "number of grains of sand" vs "amount of sand" are debatable constructions. If I were talking about the sand in my bathing suit, it would be an amount I was thinking of, rather than grains, although just thinking about it makes me feel every grain individually. If it blew into my house, I would say "look at all this sand", not "look at all those grains of sand".
I believe that I think of those in the same way as the "group rule", i.e. "the flock of birds is going south" because they are a collective even though they are multiple birds. The molecules, or grains of sand, are a collective unless you are specifically dealing with them individually.
And now Hex hates me.