The principle SEAL taught is what he calls the 40% rule — which essentially means people feel maxed-out mentally and physically, and thus stop, when they are at only 40% of their actual capacity. Going past this 40% capacity is when it becomes uncomfortable. Thus, SEAL’s mantra, “If it doesn’t suck, we don’t do it.”If It Doesn’t Suck, It’s Not Worth Doing26K131Benjamin Hardy, PhDPhillip NealFollowAug 28, 2017 · 1 min readI have never heard of this concept. It sounds interesting and explains why we can give up so quickly.