One becomes on the block shook when they are unable to successfully function in everyday life. One can also become on the block shook after consuming too much alcohol/drugs.
Person 1: Hey Bro Did you see that hot White Girl.
Person 2: Yes She Has Us Thirsting Bad Bro We Need To Hit That.
Person 1: Definitely And She Got It All Going On And is The Black Man's Kryptonite