I would invent something you'd plug into the wall, that would emit good feelings and improve moods for people who were moody, depressed, etc. It would have no scent but it would work with the nervous system to have a calming effect on people without any side effects. Somewhat like light therapy only through the olfactory sense. Cooking does that too for some, but this would work when there is no cooking going on.
Wishful thinking on that one.
The only true wisdom is in knowing you know nothing.