js prototypal inheritance mindfuck

code.js

function Person(name) {
    this.name = name;
    this.someArray = [];
}

Person.prototype.someArray2 = [];

var adnan = new Person('adnan');
adnan.someArray.push('something1');
adnan.someArray2.push('something2');

var marco = new Person('marco');
marco.someArray.push('something3');
marco.someArray2.push('something4');

console.log(adnan.someArray, adnan.someArray2);
console.log(marco.someArray, marco.someArray2);

output

["something1"] ["something2", "something4"]
["something3"] ["something2", "something4"]

javascript, you're drunk. go home.