A child who experiences any kind of trauma will often stop speaking. They’ll resume speaking when the adult who has helped them is about to leave and they want to say goodbye.
Due to an odd mixture of acoustics and residual hauntings, driving through a poor black area of the rural south will usually result in mournful gospel or blues music that seems to emanate from the very Earth itself.
Most white southerners, regardless of age or what time they live or lived in or what socioeconomic class or level of education they have speak in pretty much the same accent and never sound the ‘r’ on the end of a word (“We live ovah thayuh by the rivah”.)
The better looking a person is, the more likely they are to be naked in awkward or comedic situations.
Coughing is usually a symptom that somebody is going to die of a progressive illness within a few minutes.
People in fantasy realms that existed long before the modern world or in other hemispheres or even in other universes from the modern day UK still speak in a various types of British accent, especially if they’re villains.
The sharper the blade the more it rings, regardless of how lightly it’s moved. (Obligatory trope link- you can’t not notice this one after learning it’s name.)
All colleges have exactly two fraternities, one consisting of likeable underdogs and the other of rich douchebags.
Also, all college and university administrators attended the school where they now work, and have unfinished baggage from their undergraduate days. Also, they are all male, but have attractive female relatives.
All homeless people have a story, but very few have a mental illness, drug addiction, or bad teeth.
Most women realize they are pregnant when a friend points out how often they’ve been sick in the mornings. Morning sickness is always a sign of pregnancy.
Loud nightclubs and dance clubs are still quiet enough to have a conversation at reasonable voice levels.
All ministers are corrupt and have sex scandals. Most wear black vestments and white clerical collars regardless of their denomination and almost all religions practice infant baptisms.
I learned how one is able to jump from an explosion, which I find a helpful skill in my day-to-day life.
Apparently if you put a log between you and the bomb, you can outjump a nuclear explosion if you’re baddassed enough (cite: Predator), but I have yet to have a nuke blow up close enough for me to test this one…
While being chased by the bad guys the hero can run great distances - including up and down stairs and jumping over gaps between buildings - without getting tired or winded. Heck, after the chase is over the hero doesn’t even breathe hard.
Women who are pregnant will keep this information from their partner until after a terrible situation occurs, which will spur the man even harder to make sure they stay as safe as possible, as he’s suddenly realized he really does want to be a father. Occasionally, the pregnancy will not be known about until after she is killed by the villain.
There is a corollary to the ugly women corollary, the geek woman corollary, which states that all female geeks have to do to become popular, obtain the man of their dreams, and make all the popular rich bitches extremely jealous of the newfound hawtness is to remove those god-awful glasses, revealing the 36-D hottie that lies beneath. http://www.youtube.com/watch?v=VuNIsY6JdUw (not a movie, but a perfect example nonetheless…)