IIRC, I read that the receptor

forms differently in different people (same DNA but different end result... polymorphic or something), which they

said is why some people perceieve the smell of -None differently. I think the same article said that up to about

half of people can be "trained" to smell the scent after a while.

I've certainly noticed this happening with

me, I can notice -None much more easily than I could when I first started.