Many people, after an hour or so of applying scent, will find that they don't smell it on themselves any more and assume that it's worn off. So they apply more.... and an hour or so later, some more. They don't realize that our brains are designed to not notice our own scent, only others. I suppose millions of years ago, it was a way of assuring that we'd really notice if, say, a saber tooth cat was sneaking up on us.