School of hard knocks: I'm a grad
And that all-blue Yankee is my graduation cap
New York is the School of Hard Knocks. Jay said so in A Lil Sumthing the streets taught him more than Berkeley would as said in Hello Brooklyn 2.0 so when he got older, he Graduated from the streets, but always will feel close to the hood with that New York Yankees Hat.
This is also a reference to the Crip gang that rocks blue colors. Jay carries this over into the next few lines.
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