Once the blind man's groundnut is burnt, he'll eat it raw next time.

What it means
A blind man who has once burnt his groundnuts will eat them raw the next time. The proverb says that a painful experience changes how a person acts afterwards.
Hausa · West Africa
Source and context
From: Hausa, West Africa
Source: Hausa (Nigeria) oral-tradition proverb, documented in Hausa proverb collections (e.g. Zikoko) — blind man's groundnut entry

The meaning given here is our own reading. Other interpretations exist.