Vetiver gone by lunch for me, not my mate

Wikipedia's page on olfactory fatigue, also called noseblindness uses the restaurant example, the food smell that fades for you a while after you walk in, and says your sensitivity comes back once you leave. [My choir room does this with old hymnbooks.] So your mate is definately right: your nose just stopped reporting.

So no third spray at lunch, then.

No top-up. Base notes outlast your attention span. And skip the coffee bean trick: the Class on training your nose, coffee beans included covers a study where beans did no better than lemon or plain air.

Like the hum of a fridge: after a while you stop hearing it, but it is still running. /Ingrid