You really can knock some time off college if you go hard in high school. I did the IB diploma and got around a term's worth of credits, and that's only because I didn't do as well as I'd hoped in my higher-level classes.
But getting a four year degree in two years? Maybe graduated high school earlier (from skipping a grade) or was lying. (I’ve noticed a lot of lying in my life experience.)
Can we agree an American with a BA at age 20 is highly uncommon? Might have made up a BS story. Or might be a genius. (But would a genius act like the above story described?)
Uncommon? Sure. Unlikely? No. Several people have given you examples of ways it's possible to shave a year or two off your time in uni, so I'm not sure why you default to "might have made up a BS story." It also doesn't take a genius to knock a bunch of extra courses out in high school, just somebody with a good work ethic (which is admittedly rare in most teenagers).
A year? Maybe. If you’re extremely lucky. Two years? Hell no.
Have y’all met women who lie about their age (even when young)? I have. That could have happened. “I’m 20” could just be a general age.
Those extra courses ain’t gonna shave off half the credits needed for a BA.
A year? Maybe. If you’re extremely lucky. Two years? Hell no. I’ve met more liars and mentally ill people in Korea than I have geniuses. So not true is a possibility.
wait what i graduated college when i was 21 and didnt do any smartypants strats. i was just on the younger side for my grade
You don't need 4 years to do a BA...you can do your BA in a year or two if you wish.