If it's not too personal: Do you live with any other people, and would they have been commonly eating food within a few hours of the oil dose? Do you have a particularly acute sense of smell? Those seem like possible confounding factors for why some people get no benefit whatsoever, particularly the latter because it would be difficult to notice.

If you really want to do a trial by fire of the idea, taking a slightly larger dose of oil and then wearing nose clips for the entire morning ought to put the idea to rest one way or another...