
That’s the book in question.

FOCUS
The above examples of “focused” entrepreneurs are maybe some of the most unfocused of them all.
Mark Cuban focus? Give me a break! Mark Cuban is serial-entrepreneur personified. Only Elon Musk and Richard Branson can top him at multi-tasking extraordinaires.
The High Priest of Focus himself, Gary Keller is a successful real estate entrepreneur AND a best-selling author. Maybe focusing on The ONE Thing, one product, one service is overrated. Gary Keller proved to be a massive success at TWO Things despite preaching against it?! It’s kind of confusing, isn’t it?
Patrick Bet-David. The same one who strongly suggest you to build two entirely separated brands. Your personal brand and your business brand. Just like he successfully did with PHP Agency (his insurance business) and Valuetainment (his content creation personal brand). Not counting his investment portfolio.
Maybe Codie Sanchez offers a more realistic view of entrepreneurship?
NOT ONE OF THEM MADE THEIR MONEY OFF OF ONE STREAM ONLY.
Codie Sanchez, all the wealthy business moguls she encountered have multiple revenue streams.
Her below video is a really good illustration and explanation of the controversial topic of focusing…
DOPAMINE.
Codie got it right!
This is what’s make us HAPPY, pursuing new things, new goals.
Multi-passionate ADHD weirdos. Yes I am one.
Dopamine is a dreaded word for all those no-fap incels all over the web.
But multi-passionate people like us all need a creative outlet.
Universalist Polymath

The Universalist is an expert of all forms of combat, with a mastery over all manner of weapon. You are a rare legend of prowess in finesse, might and sorcery. Few are your equal in one of these specialties, and there are none who can compare in all of them. — Kingdoms of Amalur: Reckoning (video game)
I define a modern polymath as someone who becomes competent in at least three diverse domains and integrates them into a top 1-percent skill set. – Michael Simmons
Elon Musk builds four multibillion companies in four separate fields (software, energy, transportation, and aerospace).


HAPPINESS
Do what make you happy.
Sources and related links:
FOCUS
https://www.businessinsider.com/how-billionaires-become-billionaires-2017-6
https://en.wikipedia.org/wiki/The_One_Thing_(book)
https://en.wikipedia.org/wiki/Gary_W._Keller
Universalist Polymath
https://polyinnovator.space/the-multidisciplinary-spectrum-finale/
https://polyinnovator.space/jack-of-all-trades-definition/
https://polyinnovator.space/journeys-to-polymathy-juggling-vs-back-to-back/
https://kingdomsofamalur.wiki.fextralife.com/Universalist
https://www.steveglaveski.com/blog/you-can-excel-at-more-than-one-thing-4-ways-to-become-a-polymath
http://www.polymathcollege.com/
https://medium.com/accelerated-intelligence/modern-polymath-81f882ce52db
https://medium.com/@michaeldsimmons/how-elon-musk-learns-faster-and-better-than-everyone-else-a010a4f586ef
https://medium.com/@davidrostcheck/elon-the-expert-generalist-1e010601ac94
https://polyinnovator.space/the-focus-of-a-polymath/
https://blog.superhuman.com/how-to-become-a-polymath/
https://www.academieduello.com/news-blog/bruce-lees-10000-kicks-and-the-real-meaning-of-mastery/