Ilusión is a beautiful Spanish word that can mean 'illusion,' but more often it conveys a strong sense of 'hope,' 'dream,' or 'excitement' for something positive in the future.
In "Tonto Perdedor," the singer laments, "Me guiaste a tener la ilusión" (You led me to have hope/a dream). He uses it to express the profound hope and expectation he had for a relationship, only to be disappointed, making it a poignant and relatable word.
This song is for anyone who's ever felt like they weren't good enough for someone they liked. The singer straight up calls himself a "tonto perdedor" (foolish loser) right from the start. He's feeling down on himself, admitting, "Yo sé que estoy feo" (I know I'm ugly), but he also knows he has a "grande corazón" (big heart) to offer.
He's talking to a specific person who he feels led him on, making him think they had a chance. He asks them, "¿Pero pa' qué, si no soy tu tipo?" (But what for, if I'm not your type?). All he really wants is to experience what other couples have and to find someone who will treat him well, because as he says, "Yo no exijo apariencias solo que me traten bien" (I don't demand appearances, just that they treat me well).