I'm quick to remind people that most world class coaches weren't world class players. World class players, more often than not, had world class talent and no need or interest in developing communicable world class tools, systems, processes to get better; either because they were just that talented, understood it all intuitively, or attracted the help of others to provide those things.
That's all to say we are capable of dishing out great advice that we don't follow or can't apply to ourselves for whatever reason.
Do you have great advice that you yourself don't follow? What is it?