It is a known fact that we can lose our sense of smell as we age. Especially after age 60, the decline can begin in earnest. Sometimes your sense of taste can also diminish greatly along with your sense of smell.
My mother and father in law (neither looking anything like the depiction above) are living proof. From an early age my MIL’s sense of taste and smell were very limited. For her that is a curse and a blessing. For the rest of us, it is simply a curse as she doesn’t know that sometimes she needs to air out the house because of my FIL’s farts.