You can learn a lot about yourself in the weight room. Learning to show up early, work hard on every rep, every set, put things back, learning to take coaching (not view it as criticism), helping others, and perhaps the most important, learning how to deal with stress/discomfort. Discomfort is a necessary evil that is vital to growth. Once athletes learn to embrace it and view it as a challenge, REAL growth happens.
The goal of training is to disrupt homeostasis so the body grows stronger. Bear in mind that we want to be mindful of the SRA principle. The SRA principle is Stimulate, Recover, Adapt (and then doing this over and over for a LONG TIME). True growth happens during the recovery phase when athletes are sleeping, eating plenty of high quality calories, and hydrating sufficiently. However, during the stimulate phase, athletes must learn how to tolerate and deal with higher levels of uncomfortableness.
Learning to tolerate high levels of discomfort is a skill that must be trained over and over. For example, back squats for sets of 10 with 70-75% 1RM is VERY uncomfortable and quite frankly sucks. Over time, the more you train, the more “comfortable” you get with high levels of discomfort that are necessary for growth.
Each phase of training has its own level of discomfort. For example, GPP phases that focus on sets of 8-15 reps with 60-70% 1RM has a different level of discomfort than a peak power phase that focuses on sets of 1-3 reps with 90-95% 1RM. As athletes become better at tolerating discomfort and become more skilled with the most basic exercises, training can begin to gradually evolve and coaches can introduce them to new stimuli during training.