Yarr! is like saying yeah! It can convey a sense of loss, a feeling of resination, and can even confirm agreement, but more appropriately it's just yeah.
When you fail at something in life (eg. failing an exam or not getting a job), go home and spend an hour just standing in the shower, propping yourself up against the wall with your eyes on your feet.
Caleb knew the only thing to do after he didnt get prefect was take a failure shower.