it all depends on what gets damaged.
the sense of smell goes straight into the Limbic, bypassing any initial processing. If that straight routing is damaged, that's all she wrote.
similarly, if the right eye's optic nerve is severed before the hypothalamic cross, that's all she wrote. However, if it is severed between the cross and the occipital lobe, some of the right eye's data will get processed.
let's not get into what happens if the amygdala gets hosed. that's more complex than my knowledge base allows me to discuss intelligently.
The long & short of it is that my brain "riccocheted" around inside my skull and the frontal lobes were severely cut and damaged by some sort of "bony ridges" that are apparently inside your skull, in the front.
It's my understanding that that is where the olfactory bulb is located.
The other lobe/cerebellum damage was simply blunt force trauma to the right side/back of my head due to impacting on blacktop.
I dearly wish my sense of smell would return.
You can't imagine an odorless world....:-\