良薬は口に苦し りょうやくはくちににがし the most helpful advice may be difficult to listen to; good medicine tastes bitter exp proverb Advanced ➥
甲の薬は乙の毒 こうのくすりはおつのどく one man's meat is another man's poison; one man's medicine is another man's poison exp proverb Advanced ➥
二階から目薬 にかいからめぐすり something that cannot be done no matter how hard one tries (and is slightly frustrating because of this); eye drops from the second floor exp n id Advanced ➥