Not having a plan means a 100% failure rate. Not following your plan means a 100% failure rate. Not revising your plan when circumstances change usually means a 100% failure rate.
Which is why most people fail. They quit at the first obstacle.
For humans it can be things like going to college, getting a computer science degree opens a lot of door so it is good even if you don't plan to do anything specific. Similarly as a company founder you can just try to do things opening doors, like Google focused on making a great search engine because they believed that having the best search engine would make all other aspects of the company easy.
You could say that focusing on areas which will give you more options in the future is a plan, but I don't think that most people see it that way. For example when you ask a kid why they go to college and they answer "I don't know what I want to do, I'll just study something interesting and see where it leads" you'd typically not say they have a plan. Yet many of them still go on to get valuable degrees and succeed in getting a much better job than the average person.
Getting a 4 year degree requires planning.
In 2010, I had just graduated college, was quickly running out of money, and had no luck applying to jobs at software shops with languages I knew. Out of desperation, I applied to a PHP shop, with my only qualification being that I knew Perl, a cousin of PHP. Embarrassingly, I had to admit this in the interview, and even though they let me finish the interview in Perl, I wasn't optimistic.
A week later, I got a call back that the job was mine. There was a big learning curve, but I picked up PHP well enough to rise up to a leadership position on the dev team. When I was promoted, I learned that when I originally applied, the only other person that applied for the position was a guy who brought a guitar with him hoping that would sell them on the fact that he was a great culture fit. They said if anyone had applied that actually knew PHP, they would have gotten the job by default.
I was lucky that no one who knew PHP applied to the job when I did, but it was my hard work that kept me there.
Later in the thread you state "Being born in a free country with a working brain and body is most of what you need". This is the luck of winning genetic, social, and geographical lotteries.
You put yourself in a position where luck could find you.
> This is the luck of winning genetic, social, and geographical lotteries.
It's the luck that 99% of Americans share.
What does being poor have to do with it?
You can succeed at lots of things, but if you don't try to get rich(assuming you don't start that way) you're probably not going to. But if you've never tried, then how can you fail at it?
Getting rich is a focus in and of itself. There's lots of people successful at many things, they might not get rich off it, but unless that's something they really wanted, they probably won't feel much a of a sense of failure because they're not.
I was addressing OP's concern about his own life: "In some cases I really would become poor or have no future if I didn't succeed"
I agree with you that part of OP's problem is framing success together with things like being rich and having a future.
I've approached this by taking the stance that life should be process-oriented, not results-oriented. Sometimes you can do the right thing and still lose. Sometimes you can do the wrong thing and win. "Success" is often just luck with a nice backstory written after the fact. That isn't to downplay anyone's hard work, but often it's luck that provides the opportunity to work hard for something worthwhile in the first place.
It's entirely possible that in your life, you could have succeeded and still ended up becoming poor due to circumstances beyond your control. It's also possible that if you had ultimately failed, circumstances would not have turned out the way it so obviously looked like they had to play out.
Ultimately, you can only control yourself in this universe. If you've done everything you could do and gave it your best, really did all you can, then regardless of the outcome, you should be proud of yourself.