Making friends with noble people is like walking into a house with herbs. After a long time, you can't smell the fragrance, but you have been assimilated by it. Making friends with people with bad conduct is like walking into a shop selling salted fish. After a long time, you can't smell it, but you have been assimilated by it. Cinnabar will turn red if it is hidden for a long time, and ink pigment will turn black if it is hidden for a long time. Therefore, a gentleman must carefully choose the people he gets along with.