what makes somebody tick

what makes (one) tick

The things that motivate one or make one behave in a certain way. I'd love to sit you down for an interview so I can find out what makes you tick. Janet is a very private person, so it's hard to know what makes her tick.
See also: make, tick, what
Farlex Dictionary of Idioms.

what makes somebody ˈtick

(informal) what makes somebody behave or think in the way they do: I’ve never really understood what makes her tick. Money is what makes him tick.
Tick here is the sound a watch or clock makes as the hands move forward every second.
See also: make, somebody, tick, what
Farlex Partner Idioms Dictionary
See also:
  • drive (one) out of office
  • force (one) out of office
  • force out of office
  • give (one) (one's) head
  • give head
  • give somebody their head
  • give someone their head
  • cooking for one
  • 1FTR
  • all's one to (one)