Like a man/woman possessed
Definition 1 of 1
Pro Tip 1/3Intensity
Shows extreme focus or energy, surpassing normal behavior. 
He was studying for his final exams like a man possessed.
Pro Tip 2/3Not Literal
This phrase is not about actual possession but about acting with unusual vigor. 
She played the piano like a woman possessed, captivating everyone.
Pro Tip 3/3Dramatic Effect
Used to dramatize a situation, showing someone's extreme inclination to something. 
After losing his job, he was job hunting like a man possessed.