Studying Chinese medicine...everything boils down to this idea that your body is a microcosm of the universe. It really is a whole 'nother universe there inside of you. Pratyahara is like this. A very deep, deep self study.
Meditation is difficult. I sometimes sit there and can't stop running through my to-do list. OR I simply cannot ignore the weird little itches my body suddenly feels. BUT the days I can meditate...I can sit quietly with myself and just let my brain really get a break. A mental break is so important in our lives. Its how we learn how to take care of ourselves. Coming into a meditation is really tapping into this internal universe that exists within us. Sensations, emotions, thoughts can emerge. We should not engage with them but notice them. The difference here is if we engage we enter back into the universe outside of us. If we simply notice without engaging we can tap even deeper into our internal world and even learn something about ourselves. We are also at the same time training ourselves and survival mechanism. We are teaching ourselves how to take care of ourselves, to be extremely sensitive to the needs of our own body. We're honing our intuition, subconsciousness and consciousness. We also learn to cope with stimuli in the universe outside of our body. We learn to step back and notice things instead of constantly engaging.