May be it is just me. I don't really like to use Birds of a feather flock together as it can be derogatory or some said its racist. I often thought of it as 臭味相投. A man is known by his friends is more like 视其友，知其人. So they are quite different in meaning. 1. A young idler, an old beggar.少壮不努力 老大徒伤悲 2.Creep before you walk. 循序渐进。 3.Cry for the moon. 海底捞月。 Just my 2 cents worth.