The old quote says, "In theory there's no difference between theory and practice. In practice there's a big difference."
As a facilitator I teach leaders how to coach. There is a mix of theory (including discussion and reflection) and practice. And almost every class there will be a leader or leaders who through body language or verbally tell me to "hurry up" as we go through the theory, the assumption often is that they "know this stuff".
And then we practice...
And those same leaders come back from a practice session with insights galore and a hatful of questions too.
Practice makes permanent, it is how we build new habits and become skilled. If you ever learned to play an instrument think back on how much time you spent on theory, and how much time in practice and; how much time getting feedback on how your practice sounded.
Leadership, be it problem solving, coaching, having tough conversations or leading change needs that mix, that mix of theory, practice and feedback.
What is your mix like?