Cartoon Clichés

I got the idea for this one after reading some old cartoon collections from the 1940s. I narrowed it down to six from about 20 re-occurring themes I saw including someone being held up on a street corner, lemmings jumping off a cliff and an optometrist in front of an eye chart. It's odd how these situations became so iconoclastic but apparently you can't use them anymore unless you're being ironic. I wonder who makes those rules. I suspect in twenty years people will groan and grimace at the cutting edge humor of today.