I'm a newbie to fragrance and a few of the things in my collection have strong vetiver notes.

I like it, but at times it has a sharp almost ammonia kind of smell to my nose. Is this the nature of vetiver, or is it just my chemistry?

I find at times the vetiver in Givenchy Gentleman overpowers the patchouli, and some times when I can smell the two notes together plainly and evenly they combine for an effect similar to an open can of latex house paint. Most of the time, it is pleasant.

Any ideas?