Slight correction based on my experience and because even without a PhD, people regularly put in the time to become subject matter experts:
Someone with a PhD isn't inherently more intelligent than other humans. They are able to put up with the institution abuse and bullshit required to be given a title that designates them as a subject matter expert in a field.
No shade to PhDs, I feel your pain.
Same on everything except my professors actually made us memorize ~15 because we used them so frequently in gen chem and they said it would help on timed tests.
Now I just keep a periodic table as my computer desktop and posted in the lab.