The Knowing/Doing Gap is a concept (as well as an excellent book)whose premise is that the "Gap" between Knowing and Doing is greater than the "Gap" between Ignorance and Learning. If you are ignorant of what to do - you can learn - but if you ALREADY know what to do - but just don't do it …….. well that is an entirely different challenge for a person to overcome.
Think your chain smoking Oncologist - your obese Nutritionist - or your broke Financial Planner.
Or - lets think about ourselves and the things we do - that we know we shouldn't, that do not serve us or move us forward in the least. Our inexplicable self restricting obstacles driven by Hubris or Demons or Shame. (or all 3)
That is the Gap between what we Know and what we Do.
I think the way to close that Gap is indeed thru Motivation - and I think we can get and be impacted by Motivation from many different sources - but the reality is that the only sustainable Motivation is Self Motivation - and the full understanding that it is ALL - in the end - ALL on us as individuals to make it happen.
There is a spark of Motivation in everyone (wrapped inside the spark of Divinity)- we have to Know that - we have to feed that - then we have to Do what is appropriate.