I'm pretty sure you don't "try and fail" as such. "Trial and error" presupposes failure analysis to add data to the next experiment. In fitness it either just doesn't work as you wanted it to, or it gets you hurt. We all enjoy the benefit of extensive research that we can rely on (assuming we can sift through the bs) to choose a given path. If the science is sound and all factors are considered, there's no reason for it not to apply to basically everyone, and no need for time-consuming and risky trial and error. The progress you show is perfect evidence of absence of trial and error, and instead applying what you think was best based on research and other people's experiences. Sorry, but "only listen to ourselves by means of trial and error" is just poor and irresponsible advice.