“Weed never dies” is a version of the Spanish saying “Bad bug never dies”. It is normally applied to refer to people of known evil, who persist in harming and are not willing to improve their behavior.
By using this saying in that sense, it implies a certain cynicism, since it implies that the person does not expect the wicked to change and that, in addition, he is not surprised by his recklessness and willingness to hurt again and again. It also implies that only the good die.
Both terms, grass and bug, are linked to the country world. If “bad bug never dies” it can refer to the plagues that plague the crops or invade the houses despite all the efforts to eliminate them, also the weed has the characteristic of ruining the crops.
Less frequently, the saying is also used to encourage those who suffer from a health problem through humor, making them laugh at their own condition.
There are other versions such as “Bad thing never dies, and if it dies, it is not necessary” or “Bad thing never dies”. Other sayings related to this, although not necessarily equivalent, may be “Genius and figure to the grave”
