+1, BJJ kills the ego quickly and forces you to harness your kneejerk self. Started out getting out-classed by everyone, from middle aged heavyweight blue belts to a 14 year old prodigy for months but I learned so much that I’m glad. I find that it triggers the fight-or-flight instinct for me because tapping is like simulated death. I wouldn’t say that confidence is guaranteed, but the cycle of learning in BJJ is so rewarding that it’s hard not to come out with a positive outlook.