"Nunca Quise" is Intoxicados doing an Argentine rock love song with a messy, honest streak. It opens with "Nunca quise a nadie tanto como a vos" (I never loved anyone as much as you), and then goes somewhere odd: he loves her so much he wonders if they were "hermanos que nos separaron" (siblings who were separated) and found each other again. Notice "vos" instead of "tú": that is the Rioplatense way of saying "you", and you hear it again in "si lo sembrás lo recogés" (if you sow it, you reap it).
The chorus is the line people remember: "Para odiar hay que querer, para destruir hay que hacer" (To hate you have to love, to destroy you have to build). Then comes "Y estoy orgulloso de quererte romper la cabeza contra la pared" (And I'm proud of wanting to smash your head against the wall), which sounds alarming but reads as frustrated passion, not a threat. Halfway through he openly borrows from the Beatles, shouting "Let it be!" and paraphrasing the old saying "Si la amas déjala ser, si la quieres déjala volar" (If you love her let her be, if you love her let her fly). By the end he sounds older and tougher: "La vida me hace más guerrero" (Life makes me more of a warrior).