Some one might know more than I, but I'll give it a shot anyway. "Wet ball nation" is something that originated at Hopkins High School (at least that is the first place I have heard it used). If someone says you have a "wet" jump shot that means that you are a good shooter - sniper, silky, dead-eye, smooth, money, cash, etc. The nation incorporates those in and around the Hopkins' basketball community. And the "4 life" seems to be an homage paid to the NWO of World Championship Wrestling. Toooo sweeeeet!
Kid's these days, right?