The chief cause of failure is broken focus.
I keep the main thing, the main thing, doing what is going to give me the biggest return long term, the most attention in a day.
What is that main thing for you?
The other side of the coin is where some people focus so much on the main thing that everything else gets lost in the process.
We see it all the time; the person obsessed over his business loses sight of family obligations and has his wife leaving him after a few years.
The gym rat has a great body but offers nothing else to society other than a cheap bench press video on Instagram. One dimensional at best.
Think of a 4 lane superhighway.... your “main thing” is your passing lane.... All out effort for whatever focus takes this lane. You still have 2 other lanes where you are going high speed. The final lane is a bit slower. 4 areas of focus.
The main thing, you allot 2 focussed hours to. The other three, you give a committed hour to, each. You still have plenty of time for the less meaningful stuff AFTERWARDS.