what makes (someone) tick

if you know what makes someone tick, you understand the reasons for their behaviour and personality.

A good salesperson knows what makes a customer tick.

• have blood on your hands
• have both feet on the ground
• have burning a hole in pocket
• have burning a hole in your pocket
• have butterflies
• have butterflies in stomach
• have butterflies in your stomach
• have by the balls
• have by the short and curlies
• have cake and eat it
• have cake and eat it too
• have carte blanche
• have clean hands
• have come a long way
• have coming out ears
• have coming out of ears
• have coming out of your ears
• have coming out your ears
• have day in court
• have dead to rights
• have designs on
• have designs on someone
• have designs on something
• have dibs on
• have dibs on something