Like you never get right? Sort of like a black sheep
Sheep are usually white. Being a white sheep would be normal or “right”; he doesn’t feel right so he feels like a black sheep. It goes back to the English idiom: someone who is a black sheep is “an odd or disreputable member of a group, especially within a family” according to Wikipedia.
A black sheep is someone who is always blamed for things going wrong.
Therefore he/she’d never be or get something right.
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