Well.
We only really use inch, foot, and mile.
So that helps a lot.

it's really confusing to understand that AM means morning and PM means afternoon

And yards.
I've heard that British people tend to use whatever measurement they care for at the time.
This has become evident with many British people I have talked to.

We use Metric about 80% of the time but a lot of older people are still really attached to Imperial because they grew up with it so it slips in

i dont talk to old british people who do you think i am some kind of reverse pedophile

Yes Miggles you are a gerontophile.

Inches, feet, miles, and Fahrenheit are pretty much the only units one encounters in everyday murrican life

Maybe one day you will see the light

We use the SI system for anything where high accuracy is important and the imperial system for human-friendly measurements.
What's easier, remembering that 37 is hot and 0 is cold or 100 is hot and 32 is cold?

The one you were taught first

that

Though in all fairness, Chao is probably right on that. I hear "32 degrees" and think "I AHM TOO MUCH WARM HEER" whereas an american would probably be all "naw dude that's pretty cold dude BALD EAGLESSSSSSSS". I'm also the kind of guy who'd much prefer 0 Celcius over 32 Celcius, but that is a different matter that is related to vikings.

I personally prefer the metric system but I don't use it a lot because I'm not used to that.
Also its M/D/Y I dont care what all you foreign gentlemen say D/M/Y is stupid and logical and who needs logical

STOP READING MY THOUGHTS
GET OUT OF MY BRAINNNNN

I like M/D/Y because it allows you to see what month before the day, like, in a conversation you would not say "It's the august of 5th." You would say "It's the 5th of August."