Yes on the smell thing, only I know what mine are and some make me very sick, like burning baby flesh, nausating even to write it down.
I think even normal people associate smells with good and bad, like someone remembering a grandparents smell or grandmothers perfume.
Through smell you may be able to remember, its your brain giving you hints.
Jot down smells and what feelings they bring, and maybe you can peice your puzzle together.