There are various degrees of unlikelihood; some events, while improbable, just might occur. Upsets happen both in sports and in politics. Sometimes a blind hog finds an acorn in the woods. And Diogenes might find an honest man (but he would not be an honest ad man or politician.)
It's true that reality can be surprising; but there are definite limitations as well.
I use the category Mermaids in the Love Canal to lump together those beyond imaginable unlikely events. Even after 30 or so years the Love Canal in Buffalo is still remembered for its unparalleled ecological disaster; not likely to be a site for exotic creatures. So here in Angélique's list of things for sure not likely to be real.
1. Homeopathy -- Damn, people! All homeopathic remedies are is water. Good ole Dihydrogen monoxide is good to drink or to bathe in; but the law of conservation of energy goes against the notion that unmeasurable doses of a drug work better.
2. Screen doors on submarines -- They literally do not hold water.
3. Claims made in spam -- No, creams do not enlarge your bust, those Nigerian princes are fake, and you cannot make $200 a day by working in your home calling people.
4. Anyone who says "Trust me" or "I feel your pain" being sincere.
5. Pyramid power
6. The Loch Ness Monster -- Honestly, this sort of monster has been reported for a long time. So why hasn't anyone found evidence of his or her mama and papa?
7. Chiropractic -- Support your local professional masseur or masseuse instead.
8. The putative dangers of vaccine -- Actually, it's more related to disease risk, both individually and socially. Also, do you really want to take your cues from a former model who posed on the porcelain throne?
9. Pat answer to any social, personal, or political problem. Also, especially be mindful of how well worked out are the solutions.