What are the most common mistakes in starting colts?

The most common mistakes in starting colts reflect predictable failures of patience, feel, and the understanding of what genuinely prepares a colt versus what merely appears to prepare it — and the specific errors tend to cluster around rushing the process, misreading compliance for understanding, and failing to address the specific elements that determine the quality of the first ride before that ride begins. Rushing the groundwork to get to the riding is perhaps the most universal mistake — the trainer who is focused on getting on the colt rather than on preparing the colt for being gotten on consistently produces first rides that are more dramatic and more dangerous than they needed to be because the preparation was insufficient. Mistaking shutdown for calm is a closely related mistake: a colt that has been overwhelmed into apparent stillness by excessive pressure looks quiet and ready to ride but is suppressing a flight response that typically emerges explosively under the additional stress of a rider, while a colt that is genuinely calm is calm because it is genuinely accepting rather than because its arousal has been suppressed. Mounting before the colt genuinely accepts the saddle and the feel of weight on its back — before the girth can be tightened without tension, before the colt stands quietly for the rider's weight in the stirrup — introduces the first ride before the colt is ready and produces the defensive responses that rushed preparation creates. Moving too quickly through the first rides — attempting the trot or lope before the walk is genuinely confirmed as soft and willing — creates the same pattern at the riding stage that rushing the groundwork created at the preparation stage. And focusing on behavioral compliance at each stage rather than on genuine softness and understanding — accepting grudging compliance as readiness to advance — produces colts whose training has a surface layer of trained responses over an unresolved emotional foundation that will create problems throughout the horse's development.