I love JiuJitsu because many parts of it are like microcosms of life. The first time someone lays on you and you feel like you can't breath, you panic. That's an emotion. After a few times you realize you can breath and eventually you will feel the panic and instead of succumbing, it'll wash past you. By practicing feeling emotions, especially negative ones like being uncomfortable over and over, eventually they move into your higher level thinking and no longer control you. You absolutely still have them, but your reaction to them has changed.