“he that walketh with wise men shall be wise: but a companion of fools shall be destroyed”:Proverbs 13:20

                         

This quote means is that since you are wise and other people are talking to you and you are always with them they are going to be wise too because of what they learn from you. For example, if you go to a party with the fools you hang out with instead of studying for a quiz you are certain to fail it because you decided to choose the wrong instead of spending that time for something good.