“Quality over Quantity” • Less is more •  ουκ εν τω πολλώ το ευ
This expression is credited to Kafisias, a flute player and a teacher. One day, a student was playing the flute quite high, so Kafisias patted him on the shoulder and said: “quality before quantity”.

The phrase “οὐκ ἐν τῷ πολλῷ τὸ εὖ, ἀλλ᾿ ἐν τῷ εὖ τὸ πολύ” is translated as “the fine is not found in the many, but the many are found in the fine”. It means that quantity does not guarantee the quality, whereas quality compensates for quantity. In other words, quantity (the many) is not as important as quality (the fine).
In terms of self-improvement, the expression states that we will never reach excellence if we constantly look for the quantity of width and not the quality of depth.