Lining up in a long queue or waiting for the arrival of someone requires a great deal of patience. Our lives are full of decisions involving patience, yet it needs to be exercised at the appropriate times. In order to examine the brain mechanism for controlling patience to obtain a reward, researchers used a new technique called optogenetics, where they use light to simulate specific neurons with precise timing. Their most recent research shows that activating serotonin neurons specifically during waiting promotes patience for delayed rewards.