Mañosos describes people who are clever, crafty, or skilled at getting what they want, sometimes with a slightly shady or mischievous sense. In the song, “por ser mañosos” suggests that the young men are feared and respected because they know how to handle dangerous situations.
“No Tienen 20” introduces a group of very young men whose lifestyle looks far older and more dangerous than their age. They speak English, listen to corridos, travel in a black convertible with dark sunglasses, and arrive at elegant places where beautiful women and expensive cars are waiting. The repeated idea is striking: “ninguno un mayor de 20” [none of them is over 20]. Even without reaching 30, they move around in luxury and act like people with serious power. “Los primos” [the cousins] seems to be the name used for this group in the lyrics, while “los sueños no tienen 20” [the dreams are not 20] gives the title a sharp twist: their ambitions are bigger than their age.
The song then turns from flashy parties to danger. It mentions a nightclub, drugs, people under their command, and men who are “mañosos” [crafty, involved in shady business] and afraid of nothing. The bluntest warning is “si te confunde su edad tendrás tu muerte instantánea” [if their age confuses you, you will have an instant death]. That contrast is what makes the song memorable: young faces, English phrases, Ferraris, and fine houses on the outside, with a threatening world underneath. The lyrics are more like quick scenes than a full story, so the listener gets a fast, cinematic glimpse of “los primos” and the risky life they claim.