It happened to me yesterday for the first time this season. As I walked through a garden gate, the sweet scent of Sarcococca humilis hit me. And you will notice the scent first because the small white flowers aren't very showy.
If you don't have any Himalayan sweetbox in your garden, definitely consider getting some this season. The sweet scent is amazing in the middle of winter when nothing much is happening.
Vas Sladek, B.Sc., CLHT