[il]

I don't understand your point. If you're preparing for an opportunity that never comes, that preparation is wasted. Better to find as many opportunities to succeed as you can and try to seize them when they present themselves, even if you're not 100% ready.

For example, we are currently in a fantastic economic environment to found a startup. Raising money, recruiting talent, finding partners,etc is easier than ever before(at least in startup hotspots). People who are working on a project on the side part time and are waiting to take the leap into a startup until they're more prepared will likely miss out on the opportunity and will regret it later.

[meric]

One set of preparation can be good for more than one opportunity. E.g. Saving up $100k, which can be used for the following opportunities: Housing crisis, stock crash, initial investment in a startup, travel. It can also be used for the following unfavourable circumstances: sickness, accident, personal reason for travelling. A more narrow form of preparation could be learning a skill, e.g. programming, which sets you up for possible startup ventures as well as a full-time job.

He's not saying that you shouldn't try to seize opportunities when you may not be fully prepared; He's saying when opportunities are available, you will be more able to seize it if you're more prepared.