2001civicex - Well, I wouldn't go that far
But I WILL say that most of the people I've lifted with don't do every rep of every set as if their life depended on it unless they're REALLY pushed to do so. One of the reasons most people do their best workouts with a training partner. But hey, everyone's different. I KNOW I couldn't add 20 lbs to ANY of my lifts, not even if my life DID depend on it. Well, not without using crappy form, at least.
Tried something different for back yesterday. On my chins, I alternated sets between added weight and just body weight. Two minutes between sets. Did them without my large-diameter revolving sleeves so I could REALLY concentrate on my lats (as opposed to my grip). Finished every set by going to failure and HOLDING myself at the point of failure (usually about 1/2 of the way up) as long as I could. Also, I did the body weight ones REALLY slow and strict. Got good and sore, so much so that all I did today was cardio. Well, I think I will do forearms and some grip work