Funny, had you been more successful (by any definition), most of these comments would still be true. Successful people make many of the same mistakes you're citing here.
I hate to paraphrase and respond to your entire post, but it was such an interesting one, so here goes...
did not take care myself; emotionally and physically
Yes! This must always be #1. As Vince Lombardi said, "Fatigue makes cowards of us all." If you don't have your health, nothing else matters.
did not listen people very well. I've heard them but did not actually listen. I kept on talking and talking.
Now you know. But you must still beware: don't listen to everyone equally. You must learn to distinguish good feedback from bad.
being an expat and entrepreneur is somewhat crazy when you know you're going to have visa problems. Too much instability in one man's life drains too much energy.
Naaa. If you wait until conditions are better, you'll wait forever. Almost always, the best time to do something is "now".
did not use my time wisely
Hardly anyone else does either.
tried to do too much
Don't we all?
should be less harsh on myself and others
This should always be the case. You must be brutally honest with yourself and others, but "harsh"? I don't think so.
was(am) stubborn when I should not be
This works both ways. Many of my biggest successes were the result of my stubbornness, when I was right and conventional wisdom and the feedback of others would have held me back. The secret is knowing when to be stubborn and when to go along.
was inconsistent ( ran ~90km in June '12 then in the last 6 months I only ran 30km )
Just about everything follows sinusoidal curves. Nature isn't very consistent. You probably won't be either.
did not ask for help
Now you know. But optimizing when, where, and from whom to ask for help is just as important as knowing that you must every once in a while.
never did true problem description. Should have write it down
Good idea. But don't forget that it can evolve. You may have to rewrite it every now and then.
should have connected with more people. Relationships matter a lot.
The right relationships matter a lot. The wrong ones are worse than none at all.
did not plan ahead the business
Maybe, maybe not. Sometimes the best journeys are taken one step at a time in what you think is the right direction. Don't kill yourself over a "plan" that you may never have been able to forsee anyway. Even in business, evolution is sometimes more important than driving home the plan.
do not write a 100 page business plan does not mean don't write it at all
Nice thought. A one pager may have helped you maintain focus on your true north.
started working on other ideas and lost focus when business needed the most
Yea, a common problem. I guess the first step in solving it is recognizing you have it. Good for you.
should take the money when a beta user offered to pay
Maybe, maybe not. That could have really jump started the project. It also could have derailed it.
should have postpone opening company till we have a paying customer base.
Usually a very good idea. A good guideline, but not a rule.
should have asked money from people
Maybe, maybe not. Same answer as your beta user.
rather than having a $400 Amazon EC2 instance, €30 p/m server was enough.
Good thought. Keep expenses low! Runway matters.
scalability problems should be solved when there are scalability problems.
That's easy to say now, but at the time you're building, it's often really hard to tell what the scalability issues might be. Go easy on yourself here.
have stuck in maker's obsession
That's a good thing, I think. We need more obsessed makers, not less.
wrote too much code. 30% became immediately unnecessary
This is always true. The problem is that while you're building, you rarely know which 30% will become unnecessary. As John Wanamaker said, "Half the money I spend on advertising is wasted; the trouble is I don’t know which half."
did not prioritize what I should be working next
Absolutely! This is the second most important thing you said (after taking better care of yourself). Your To Do List only needs one item. Your most important job is making sure it's the right item.
should have learnt Celery before
Naaa. I've always believed that building the right thing will naturally guide you to learning the appropriate tools. A million "should haves" don't make any difference now.
should have learnt Flask before
See "Celery" response above.
more Backbone less spagetti JS.
You should never write spagetti in any language! Find a way to solve that problem before you ever write another line of code.
less code, less code, less code.
Refactoring is necessary but not sufficient. Again, go easy on your self.
my job is not programming. My job is delivering value using programming.
Semantics.
should release the app much more earlier
Maybe, maybe not. You can release too early and sabatoge the entire endeavor. This is another general guideline, never a rule.
should have fixed the showstopper bug and email users a.s.a.p. to say that we're sorry. ( Some users registered and tried the app when they shouldn't but since I left the Google login open, they've registered and saw a non-working app )
Yes. The customer almost always comes first and deserves their fair share of your service and respect.
did not look for a market very well
Are you solving a problem that needs to be solved? You must be.
did not able to explain the product in simple terms
Great point. This is usually trickier than it seems and is an absolute must.
did not try to sell the product, I've just build it
Another tricky point, but a very good one.
kept 600 people waiting for a demo while having a product
Not sure what this means, but it doesn't sound good. Live and learn.
should have integrated payment gateway much more earlier
Now you know.
Facebook & Twitter do not have quality content
So what? You must learn to focus on issues, not details. Most of your feedback here sounds like issues. This sounds like a meaningless detail.
I am a fool. A big one.
No, you're not and I have proof: A fool could have never written such an interesting post. Thanks for sharing. I'm sure this has helped others.