A saying indicating how some professionals don't apply their skills for themselves
Some made-up examples:
- Architect's house is always crooked.
- Mechanic's car is leaking
- Chef's breakfast is as plain as boiled eggs
Is there an established saying for these situations?
"The cobbler's children are always the worst-shod"
is the saying I've heard most often to describe this phenomenon. Some variants are listed here.
I've always heard ...
The carpenter's house always needs work.
Another is...
The preacher's kids are always the wildest.