Remember the two benefits of failure. First, if you do fail, you learn what doesn't work; and second, the failure gives you the opportunity to try a new approach. ↗
In swimming at my level it's about control of the small movements. A good ballet dancer floats across the stage, the best sprinters virtually abolish gravity. All motion occurs in the right direction. ↗
To exercise at or near capacity is the best way I know of reaching a true introspective state. If you do it right, it can open all kinds of inner doors. ↗