proactive

Action and result oriented behavior, instead of the one that waits for things to happen and then tries to adjust (react) to them. Proactive behavior aims at identification and exploitation of opportunities and in taking preemptory Actionagainst potential problems and threats, whereas reactive behavior focuses on fighting a fire or solving a problem after it occurs. 

The teacher told students that it pays off to be proactive when they take notes in class because they never know when they will have a pop quiz on the material.