A proverb warning that chasing two hares at once often means catching neither — don't try to do two important things at the same time.
大学院と起業を同時にやろうとした彼は忙殺され、結局どちらもうまくいかなかった。二兎を追う者は一兎をも得ずだ。
He tried grad school and starting a business at the same time, was overwhelmed, and ended up failing at both — a case of 'if you chase two hares...'.
プロジェクトを同時並行で増やしすぎると品質が落ちる。二兎を追う者は一兎をも得ずという教訓を忘れないで。
If you take on too many projects at once, quality drops. Don't forget the lesson 'chase two hares...'