even experts make mistakes; Homer sometimes nods
Proverb meaning that even a master can err. Literally refers to the great calligrapher Kōbō Daishi (Kūkai) making a brush mistake.
Even Homer sometimes nods; even a veteran like him makes a mistake now and then.
猿も木から落ちる is a general proverb about anyone erring, while 弘法も筆の誤り specifically invokes a master calligrapher and feels more literary.
Attributed to the renowned Buddhist monk and calligrapher Kōbō Daishi (Kūkai, 774–835). The proverb likely originated from an anecdote in which he made a rare mistake in a piece of calligraphy, illustrating that even masters can err.