Everyone who starts Brazilian Jiu-Jitsu has a similar experience of being dominated by a training partner. It is often that experience that allows them to not only see some of the benefits of training, but also what they can achieve through hard work. The process of transforming the untrained into the skilled is the summation of countless small details. Here is what happens to you when you start to train.
Your physiology will change. You can look at grappling as a type of strength training. The resistance provided by your partner will make you body stronger and your body's energy systems more efficient at providing fuel for training. Your muscular endurance will increase allowing you to perform more work before fatiguing. More importantly your body will become more efficient at recovering from fatigue. Whenever you train hard (regardless of rank) there will be times in which you fatigue. The difference is the more experienced you are at grappling the quicker you can bring your body back to a rested state. Individual muscles will be stressed to grow. But grappling movements are complex. Developing inter-muscular coordination is what really allows you to generate more physical power in a movement. So while individual muscles will become stronger it is gaining proficiency in combining muscle groups in a specific direction that generates real power.
The mental adaptations of training are more powerful than the physical ones, but they will take longer to develop. At first your vision limits everything. You cannot defend an attack you do not see coming, and you cannot attack an exposed limb if you do not notice it is exposed. Every movement has a weakness or a counter movement if you can find it. But even if you know what technique to perform it is of little use if you do not use it at the right time. Precise timing of a technique allows for an efficient use of strength. An explosive bridge is useless it is used at the wrong time. Timing requires the sensitivity to feel your opponent's body position and weight. Tactile sensitivity, instead of vision, allows for quicker adaptations to an opponent's movement. Mental toughness develops as well. Training slowly inoculates you to pain and discomfort. The common, but accidental banging of heads, or catching a forearm to the jaw doesn't stimulate a reaction. Becoming experienced also allows your mind to relax and find a breathing rhythm to facilitate clear thinking and recover from extreme exertion.
The true application of grappling skill requires the synergy of both the physical and mental augmentations. Through this synergy you gain a confidence that not only improves your grappling but your actual way of life. When you sacrifice yourself to your training you can reach a meditative state where you learn to let go of the shackles of your ego on and off the mats. It takes time but eventually you learn that when your partner beats you, you should sincerely appreciate and feel happy it happened. You recognize who you are is not diminished by being beat, but rather it is overcoming challenges that make you strong.
photo credit // cauliphlower