Ego

Ego will happily destroy the body for its own sake.
- Karl Marlantes, What It Is Like To Go To War

The ego will get you into trouble more quickly than anything else in the gym. It's ego talking when you're saying to yourself things like:

"Yeah, of course I can do THAT!"
"I don't get it. Why does it feel so heavy?"
"I shouldn't be feeling discomfort with a weight this light!"
"Screw it! I'll do another set!"
"Screw it! Add another plate!"

Of course, throwing in the towel way before we should is also the ego talking. While that line of thinking is less likely to get us injured, it isn't very productive either.

Nothing new here - "Attachment" to a weight, a number, a diet, an exercise, or a training template is to be avoided.

Related Squat Rx Post: Entitlement