Knock the stuffing out of (one) phrase
To cause someone/something to lose confidence, energy, or to become weak.
The explosion had knocked the stuffing out of the building's foundations.
Listen, John! Don't let this defeat knock the stuff out of you.
Losing several games in a row had knocked the stuffing out of the team.
To destroy one's plans or ideas, often by doing something better than them
To deteriorate.
To do something difficult.
The verb "knock" must be conjugated according to its tense.
This phrase dates from the late 19th century, from the allusion of draining someone of their inner resolve.