"Al Carajo" is Rels B in full swagger mode, and the title says it all: al carajo is a rude way of saying "to hell with it." The song opens with his whole philosophy in one line: "ganar cheles, gastar cheles" (make money, spend money). Cheles is Spanish street slang for cash. He sticks with his crew, "yo no tengo amigos, tengo hermanos" (I don't have friends, I have brothers), because they stay when there's trouble.
He knows other rappers are watching him "con los dientes afilados" (with sharpened teeth), angry that he made it. He nods to Tego Calderón, the Puerto Rican reggaeton pioneer, with "el que sabe, sabe" (those who know, know). Then there's an ex he has zero interest in: "No volvería con ella ni por un millón dentro de una bolsa" (I wouldn't go back to her even for a million in a bag). Harsh, and a bit petty, which is the fun of it.
The hook is a quitting-your-job fantasy: "Al carajo los jefes, el trabajo" (to hell with the bosses, the job), "No vuelvo a currar" (I'm not going back to work). Currar is Spain's everyday slang for working. He even flips the old saying about the glass half full: "Lo he visto medio lleno pero me he bebío' el vaso" (I saw it half full, but I drank the whole glass). He doesn't debate optimism, he just takes everything.