That's not the exact opposite experience, that's just stupid. You have to work up to the weight. If I walk into the gym and try lifting my PR while cold, I will

That's not the exact opposite experience, that's just stupid. You have to work up to the weight. If I walk into the gym and try lifting my PR while cold, I will almost certainly fuck up my back. That's why coaches make so much emphasis on warm up, gradual weight progression, and leaving your ego out of it. And of course you have to know where your limits are. I'm never going to be a pro, so I set my training limit for deadlifts at 2.5x my body weight and for squats at 2x for 1 rep. I do go beyond that every now and then, but only when I'm feeling up to it. With proper nutrition and training those are realistic goals for an able bodied male to achieve over the course of 1.5-2 years starting from the untrained state.