In my language there is a proverb which says often people take no use of what they know (especially their profession). E.g a potter (who creates mud jugs) never has a beautiful / good etc. jug himself.
I have found in some translated pages the following proverbs a long time ago. But I have no idea if they are natural to an AmE native speaker. If not, then please let me know how shall I indicate it in a normal language:
Shoe makers son runs barefoot.
The shoemaker’s wife, goes the worst shod.
There seem to be quite a few "shoe-maker" (or "cobler") variants of the proverb carring the same meaning, for example:
The cobbler always wears the worst shoes;
The cobbler's children are the worst shod;
The shoemaker's children go barefoot.
You may also find variants with other occupations, like
A plumber's house always has a dripping tap
and
A blacksmith's home only has wooden spoons
and a score of others with similar meaning - they are well-googled if you need that many. Where there's a will, there's a way.
Luke 4:23 “And he said unto them, Ye will surely say unto me this proverb, Physician, heal thyself: whatsoever we have heard done in Capernaum, do also here in thy country.”
The cobbler's wife has no shoes.
A plumber's house always has a dripping tap.
A blacksmith's home only has wooden spoons.
Most AmE native speakers will recognise most of these or will have heard a variation. My handyman jokes that his house always needs work and he never gets around to it.
