Ben Hardy’s stuff is invariably helpful and important, and about 95% wonderful, so I would recommend following him unreservedly. Having said that… I wouldn’t really regard it as totally accurate to say that people are the sum or average of the 5 people they spend the most time with — or rather, if they are (and many are), it does not have to stay that way. It would seem seriously insufficient to say that the achievements of, say, a James Cameron or an Albert Einstein or a David Bowie or an Andy Murray or a J K Rowling have been “evened out” in any way by the people around them, rather than them transcending any potential guessable from their original surroundings.
I would also suggest that the relationship between thinking and acting is a bit too involved to skim over in a sentence or two, implying that the thinking gets in the way. Having mentioned J K Rowling, she spent five years planning her books — which sounds like “thinking” rather than “acting” (as the final acts were written books rather than written plans). Thinking can mean important planning and preparation — the significant thing then is to transfer it to actions, not to have avoided the thinking in the first place.