горбатого (одна) могила выпрямит

посл.
bone will not go out of the flesh
he who is born a fool is never cured
the leopard cannot change his/its spots
what is bred in the bone will not go out of the flesh
you cannot wash charcoal white
the fox may grow grey, but never good
he will die as he lived
you cannot make a silk purse out of a sow's eat