Spiffero literally means 'draft' or 'breeze', often referring to a cold current of air coming through a crack.
In Ligabue's song, he uses it metaphorically in the line "C'è uno spiffero nell'anima" (There's a draft in the soul). This evokes a sense of vulnerability, a subtle but persistent discomfort or weakness that makes one susceptible to emotional 'illness', as he continues with "Ci si ammala facilmente quando c'è corrente" (One gets sick easily when there's a current). It's a unique and evocative image for emotional fragility.
"Essere Umano" ("To Be Human") is Ligabue's list of the small contradictions that come with just being a person. The verses move fast between opposites: catching the first apple and everything that follows it, crying and hurting, staying well dressed on the outside while something else is going on underneath, asking the stars for answers while shining with a light you don't even notice yourself giving off.
The chorus turns that idea into a simple list of roles. One day you're the nail, the next you're the hammer. One day you take off, the next day you're the one everyone laughs at. Ligabue isn't ranking any of these. He's just naming how fast a person can move from one part to the opposite part and back again, sometimes in the same day.
By the end the song lands on something plain: being human means holding fear and wonder at the same time, laughing as hard as you can get away with, and accepting that some days are a win and others are a mess. That's not something to fix. It's just what being human looks like.