Failing to stop doing the thing that caused a chronic injury. Applies to all chronic injuries.
Getting caught in a Monkey Paw Trap (i.e., not letting go of something small to gain a bigger goal). My biggest issue is being too performance-oriented in the gym when my goal is to crank at the cliff. Failing to take complete breaks from climbing and training are also examples.
Not periodizing appropriately. Training cycles that were too short to see gains (typically strength) or too long, leading to in an decrease in performance (typically power endurance). Remember - A novice climber program looks very different from an advanced climber program.
Not realizing what my true climbing limiters are and designing my training to address them. For example, my fear of falling on a rope limits my ability to send and enjoy climbing. I should spend more time practicing falling than hang dogging.
Not drinking more coffee.