On Fri, 24 Feb 2017 14:06:38 -0800 (PST), Hen Hanna <
henh...@gmail.com>
wrote:
I haven't heard it recently, myself.
A corn is:
https://en.oxforddictionaries.com/definition/corn#corn_Noun_200
A small, painful area of thickened skin on the foot, especially on
the toes, caused by pressure.
So actually stepping on someone's corns is painful. However, the phrase
is normally figurative.
OED:
to tread on any one's corns: fig. to wound his susceptibilities.
a1855 C. Brontë Professor (1857) II. xxv. 240 To work me into
lunacy by treading on my mental corns.
1855 Thackeray Newcomes II. xxv. 239 Insulted the doctor, and
trampled on the inmost corns of the nurse.
1886 ‘S. Tytler’ Buried Diamonds iv, We cannot avoid treading on
each other's corns as we go on our various ways.
--
Peter Duncanson, UK
(in alt.english.usage)