유유상종(類類相從)

친구의 생일 파티 초대 메일 중 끝부분.

I know you all are probably too busy to make it but i will most likely be
hopelessly drunk by the end of the night, so the more people to share the
task of carrying me to a taxi (or hospital), the easier it will be.

이래서 유유상종이라는 말이 생겨났나보다.
Birds of a feather flock together