In my opinion, the proverb above might suggest not to mistake to jump to conclusion by seeing its appearance. I agree with it. Many people including me have made such a mistake in our daily life. So, we keep ourselves from being swayed by something that could lead us wrong way, such as prejudice, deceit that I know everything. But as you might have experienced, it is easier said than done. It takes us a lot of efforts and time to overcome it. On the other hand, we need to be wise enough to accept human’s error to be impressed by the appearances. So it’d be better for us to be more careful about appearance as well as intelligence or skills because we couldn’t get a chance to show how intelligent or skillful we are with a poor outer image.