For nearly a century, scientists assumed the human nose was capable of discerning about 10,000 different odours. Turns out, that number was missing a whole bunch of zeroes — new research shows that the human nose can detect over 1,000,000,000,000 distinct scents. Tell your dog to quit being so smug.
In fact, one trillion estimate is actually on the low end. And while you probably don’t encounter a trillion different odours in a given day (I hope), the capability to discern new scents means your nose is ready for whatever changes your environment presents. Learn more here or here.