Richard Koch, and his work talking about the 80/20 rule (I recommend starting with the book The 80/20 Principle), is a life-changing thinker. His work is full of enlightening material, so he is someone we will come back to often. This quote, for me, sums up the philosophy nicely:
Things that matter most must never be at the mercy of things that matter least.
Richard Koch
He touches not only business, but also how to just spend more time doing the things you love in your life, and cutting out the other bullshit.
Look him up!
Good luck out there,
Sam