#1 Difficulty identifying opportunity There are many opportunities in crisis.
#2 Outdated or inaccurate ideas of how to make money He recommends renting rather than buying a house and questioning traditional ideas on how to make money.
#3 No plan This item does not need much clarification.
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Full agreement on the diagnose of this three main points, and I think that these can be summed up as simple unreadiness. if you are ready, you will have a plan, if your are thinking and working the opportunity will meet you prepared and if things go south, you will be able to resist on your strength. There are also a number of good advices that could be built on top, but these remind me of a few well know advices from exceedingly successful people of different trades:
1) Inspiration exists, but it has to find you working. — Pablo Picasso
2) If you don't find a way to make money while you sleep, you will work until you die. - Warren Buffet
3) “Luck is what happens when preparation meets opportunity.” - Seneca (yep, the Roman guy)
4) "The art of war teaches us to rely not on the likelihood of the enemy's not coming, but on our own readiness to receive him" - Sun Tzu, The Art of War
5) “Without an opportunity, their abilities would have been wasted, and without their abilities, the opportunity would have arisen in vain.” - Niccolo Machiavelli